Origin: Jack saw examined Aaron's mother before his birth.
Since Then: Jack saw Aaron soon after he was born, and Claire occasionally consulted him about the baby's health. Off-island, Jack learned he was the child's uncle, and he initially refused to see him. He eventually changed his mind, and he helped raise Aaron. He read to the boy from the same book his father had read to him years before. He and Kate later broke up, and Kate said Aaron missed his presence.
Origin: Sayid returning from the balloon, with proof Ben was lying about his identity.
Prize: Free will. Ben is an effective conman who has been directly and indirectly acting to manipulate Jack. Jack is both smart and stubborn, and despises being controlled.
Fuel: Jack took Ben prisoner and locked him in the vault, where he lied about his identity, even under torture from Sayid ("One of Them"). During his captivity, Ben manipulated Locke to widen the rift between Locke and Jack ("Lockdown"). After Ben's escape, Jack believed that Ben shot Libby, Ana Lucia, and Michael, until Michael confessed. Shortly after, Ben took Jack, Kate, and Sawyer prisoner after his escape and locked them up separately on Hydra Island ("Live Together, Die Alone, Part 1"). He revealed to Jack that he had a tumor on his spine and that he wanted Jack to operate on it, to which Jack consented ("The Cost of Living"). During the surgery, Jack punctured Ben's kidney to make him a hostage and give Kate time to escape. ("I Do") Jack did eventually sew up the puncture and finish the operation successfully. ("Not in Portland"). Jack and Ben confronted each other once more when Jack was going to the radio tower. His hatred was so strong, that he would kill him once they got off of the island so Ben would know he failed ("Through the Looking Glass, Part 1"). Ben afterwards continuously ridicules Jack once Jack finds out that something about the situation isn't right. Ben leaves with Locke and goes back to the Barracks, since they share the same views on the people coming to the Island ("The Beginning of the End"). It is later revealed that Ben strongly spites Jack due to the fact that he has won Juliet's affections over, and he has so far been unsuccessful ("The Other Woman"). Three years after Jack left the Island, Ben comes to him a Hoffs Dawler Funeral Home when Jack breaks into in the middle of the night. He tells him that Jack has gotten dark thoughts and asked if "he" told him that Ben had left the Island. Ben tells him that the only way to go back to the Island is to get everyone who has left the Island and then the Island would let him return. Ben also says that he needs to carry the body of John Locke back to the Island, also known as Jeremy Bentham. ("There's No Place Like Home, Part 2")
Resolved: Yes. Ben and Jack maintain a successful partnership in their efforts to return the Oceanic 6 to the Island ("The Little Prince"). While a brief tension erupts after Ben has Kate's legal custody of Aaron threatened ("This Place Is Death"), all appears to be forgiven on board Ajira 316. During the flight, Jack turns to Ben for console after reading Locke's suicide note. Ben assures Jack that it wasn't his fault. ("316"). Upon returning to the Island, Ben ultimately joins Hugo in aiding Jack's final mission to restore the light to the Island. Jack succeeds, and dies with Ben as an ally ("The End").
Origin: Christian told Jack as a child not to try and fix everything all the time because he wouldnt have what it takes when he failed to do so.
Prize: Control over Jack's destiny. Christian is fighting to regain Jack's respect, Jack is fighting to free himself of his father's influence.
Fuel: Christian pressured Jack to sign a report that a patient Christian had operated while drunk arrived beyond hope of recovery. Upon finding out that the patient had been pregnant, Jack reversed his statement and turned Christian in. Christian lost his license and continued to struggle with alcohol ("All the Best Cowboys Have Daddy Issues"). Jack's wife, Sarah, sponsored Christian into Alcoholics Anonymous and Jack misinterpreted this as an inappropriate relationship between his wife and his father. He followed his father to an AA meeting where he punched him out ("A Tale of Two Cities"). Christian caught a flight to Australia and went on a bender ("Outlaws"). Jack's mother sent him to Australia to retrieve Christian ("White Rabbit").
Resolved: Yes. While Christian died with many of their issues unresolved, in the flash-sideways timeline they forgive each other instantly since they are both happy just to be reunited once more. They each tell each other how much they love each other and Christian helps Jack let go. ("The End")
Since Then: The two first ran into each other at a stadium in Los Angeles, and they met again on the Island. They escaped the island together, and Jack warned him as they parted to beware of Widmore. When Desmond returned to the Island, Jack, now the Island's protector, led him to the Heart. Desmond descended, telling Jack he would go somewhere else where they could be with their loved ones. He was wrong, and Jack helped him escape from the Heart. They met again on a plane in a flash sideways, and they hugged before they moved on together.
Origin: Jack, a DHARMA Initiative janitor, entered Eloise's camp soon after a man who claimed to be her son.
Since Then: Jack convinced Eloise that he came from the future, and asked her to lead him to the Others' buried bomb. Eloise agreed, alegedly to reset time, but according to Sayid, she really hoped detonating it would wipe out the DHARMA initiative. Richard knocked Eloise out while they were retrieving the bomb, as as far as Eloise knew, he died while trying to detonate its core.
Years later, off-island, Eloise worked to send Jack and the other Oceanic 6 members back to the island. She spoke to Jack alone, explaining the importance of a proxy in returning the island. Her suggestion to give something of hisfather's to Locke's body angered him, but his frustration failed to move Eloise.
Origin: Ethan approached Jack with some medicine that he'd allegedly found in the wreckage. The two talked of Claire's upcmoing labor.
Since Then: When Ethan kidnapped Claire and Charlie, Jack followed their trail with Kate. Ethan fought Jack, besting him easily and warning him not to follow further. Jack later set up a trap for Ethan, using Claire as bait. The survivors managed to ambush Ethan, and Jack this time managed to knock Ethan to the ground. He then kicked him repeatedly. Before he could interrogate the Other, Charlie shot him.
Origin: Jack recruited Hurley to help Claire right after the crash. Falling wreckage then nearly killed both, and Jack had to save them.
Since Then: Hurley began helping Jack take care of the camp. He discovered Kate's mugshot, and was surprised by Jack's indifference, and he passed out on Ed Mars while Jack tried to treat him. Some days later, Hurley built a golf course, and though Jack initially insulted the project, he quickly joined in. Hurley later began an island census with Jack';s approval, and when he let on a search for Danielle, Jack led a party to find him. The two together gathered dynamite from the Black Rock, and after they blew their way into the Hatch, Jack put Hurley in charge of allocating its supplies. Jack's deference to his final decision surprised Hurley. Libby's death convinced Hurley to join Jack in a trek to the Others, but they turned Hurley back. Jack eventually returned, and Hurley accompanied him, along with most of the camp, on a trek to the radio tower.
When the camp split, Hurley went with Locke over Jack, a decision he later regretted. The two reunited awkwardly some time later and managed to escape the island together. Hurley disagreed with Jack's plan to lie about their adventures, but he eventually gave in. Off-island, Hurley attended Jack's father's funeral, and Jack attended his birthday party. Jack saw Hurley's arrest on the news, and when Hurley committed himself to Santa Rosa, Jack came to visit him. The meeting turned sour quickly, and Hurley warned Jack against raising Aaron and said someone would soon visit him. When a series of comic adventures left Hurley with Sayid's unconscious body, he called Jack for help. The two separately ended up on Ajira 316, and Jack helped Hurley out of the water when they returned to the Island. They each joined the DHARMA Initiative. When Jack got involved in a gunfight, Hurley arrived with a van to save him.
Both ended up traveling to 2007 and went to the Temple. Hurley brought Jack to the Lighthouse on Jacob's instructions, and they later together dealt with a suicidal Richard Alpert. Jack followed Hurley's lead for a bit, and agreed to visit Locke. They sailed together to Hydra Island, but Jack jumped off the ship and later saved Hurley from Widmore's cages. On the submarine later, Jack gave Hurley instructions to save Kate. They trekked together to face the Man in Black, and Hurley offered his support when they separated before Jack visited the Heart. Hurley later chose to stay on the island with Jack rather than try to escape, and Jack inducted him as the island's new protector. Hurley hoped to save Jack from the Heart once it relit, but he could not.
Since Then: Of the main survivors, Jack interacted with Jin least. Jin knew no English right after the crash, so the two did not talk at first. When Claire went into labor, however, Jin ran to Jack to summon him. Jin left on the raft shortly after, and he told his wife to say with Jack for safety. Some weeks later, Jin volunteered to stay in the camp to put Jack's plan against the Others into effect. He stayed with Jack's half of the camp when it split, and he remained on the Island after Jack escaped.
Jin traveled to 1974 and spent three years on the Island. Jack then returned, and Jin was the first of the DHARMA Initiative to spot him. Both men ended up returning to 2007, where they spent much of their remaining time alive in separate camps. When the submarine they had boarded was sinking, Jack offered Jin the last oxygen tank. Jin refused it, saying that Jack could not escape without it.
Origin: Jack met Juliet on Hydra Island while he was being held captive by the Others of which she was a member of for the past three years. She became his main contact during his captivity, bringing him food and water.
Since Then: When Jack discovered that Ben was afflicted with a large tumor on his spinal cord Juliet asked Jack to perform the surgery, but with the intention to kill Ben and make it look like an accident. Jack told both Ben and Juliet that he wouldn’t perform the surgery at all, then changed his mind after they used Kate and Sawyer as leverage. In order to save his own life, Ben ordered Juliet to help Sawyer and Kate escape, and in exchange, he promised Juliet he’d let her go home. Juliet shot Pickett in order to get this task accomplished. Soon afterwards, Juliet was held responsible for her crime and ordered to be executed by the Others’ Isabel. Jack told Ben that if Ben commutes Juliet’s sentence, he will take care of Ben to ensure Ben’s health return to normal. Ben agreed. During a struggle with Kate, Juliet informed Kate that Kate had hurt Jack by sleeping with Sawyer. When it came time for Jack, Kate and Sayid to head back to the beach, Jack insisted that Juliet come back with them. He later told Juliet that she was now ‘one of them [the survivors]’. Although it was revealed that Juliet was still working for Ben in a plot to kidnap the pregnant female castaways, she revealed Ben’s plan to Jack, and the two hatched a plan to foil Ben. Juliet has claimed to Jack that Ben thinks Juliet belongs to him [Ben]. Juliet expressed her fear for Jack’s safety while telling him of her feelings for him. Jack reassured her that he’s not afraid of Ben and that Ben can come and find him. After performing an appendectomy on Jack, Juliet tells Kate that he kissed her [Juliet], but tells Kate that he's in love with someone else [Kate].
Origin: They met on the day of the crash when Kate sewed up Jack's wound.
Since Then: The two collaborated on numerous activities in the camp, from playing golf to rescuing Charlie. Kate resisted Jack's early push to move to the caves, still hoping for rescue, The two spent time in the Swan together, and Kate kissed Jack soon after they entered it and later apologized for this. The Others kidnapped the two of them, and Jack stumbled upon a video monitor of her and Sawyer having sex. He helped them escape the camp but stayed behind, and Kate returned to rescue him, only to find him doing fine. The camp split, and Kate initially stayed with Jack but later moved to the Barracks for a bit. Back on the beach, she helped Juliet remove his appendix. The the escaped the island together, and Jack testified as a character witness at her trial. He initially refused to come see Aaron, but he and Kate later became engaged before breaking up. Jack eventually convinced her o return to the island, where she tried and failed to get him to operate on young Ben. His plan to reset time shocked her, but she eventually gave in. In 2007, Jack chose to stay on the island, and Kate kissed him goodbye. He died soon after. They reunited in the flash sideways and moved on with their friends.
Origin: Locke lied about the cause of Boone's injuries, which Jack felt contributed directly to his death.
Prize: For Jack- Getting off of the island; For Locke - To make sure everyone stays on the island and prevent anyone else coming to it. Also pride and leadership among the survivors.
Fuel: From the time that they arrived on the Island, Locke threatened Jack's leadership. Many survivors trusted Locke over with their lives. Locke withheld knowledge of the Hatch, which cost him Jack's trust ("Do No Harm"). Their time living together in the Hatch extended their rivalry. The two's arguments became such a constant distraction that even Ana Lucia commented how "Jack and Locke are busy worrying about Locke and Jack." Locke conspired with Sayid to interrogate Henry Gale. Locke only gave in to Jack's demand to halt it when Jack threatened him with the countdown timer. ("One of Them"). Ben noted their conflict and baited Locke with the knowledge ("Lockdown"). Later, when Jack was imprisoned by the Others, Locke destroyed their submarine, which Jack planned to use to leave the Island ("The Man from Tallahassee"). Locke later killed Naomi and threatened to shoot Jack if he called the freighter.("Through the Looking Glass, Part 1"). Jack tried to kill him when they next met. Locke led a group of survivors to the Barracks, while Jack's group stayed at the beach, hoping for rescue. ("The Beginning of the End") Jack had a hard time keeping people from going to Locke's camp t. ("Ji Yeon") At their next meeting, Locke tried and failed to keep Jack on the island. When Locke moved the island, Jack refused to believe what he saw. Three years later, Locke visited Jack, and when he died, only Jack attended the funeral.
Resolved: Yes. While Locke died with many of their issues unresolved, Jack took Locke's words to heart. When he eventually faced off with The Man in Black who has taken the form of Locke, Jack told him that he disrespected Locke's memory by wearing his face, and that he wished he could have told Locke that he was right. After death, Jack and Locke come to forgive one another and Jack fixed Locke's paralysis. ("The End")
Origin: Jack noticed Rose's nervousness on the flight they shared. He told her she needn't worry, the first of many wrong pronouncements.
Since Then: Jack kept her company on their first days on the island, when she sat alone, pining for her husband. Weeks later, she told him she was happy to see him out of the hatch. When Bernard tried to build an S.O.S. sign, Rose tried to defer to Jack. She acted more skeptical of his skills later on, when his plan to attack the Others endangered Bernard. When the camp split, Rose trusted Jack more than Locke, so she stayed with him even though he wanted to find rescue. Then when Jack caught appendicitis, Rose suggested the island was punishing him for trying to leave. Jack left nonetheless, and he died before seeing Rose again. They met in the afterlife, again on Oceanic 815. This time, however, Rose reassured Jack, telling him he could "let go".
Origin: Sarah had been involved in a collision with an SUV (driven by Adam Rutherford, Shannon's father) that left her paralyzed from the waist down. Despite all the odds, Jack fixed her, which ultimately led to their marriage.
Since Then: The night before the wedding, Jack had great difficulty writing his vows and voiced some his doubt to his father, Christian Shephard, who reassured his son that commitment is what makes Jack "tick." During the wedding ceremony, an emotional Jack stated as his unwritten vow that it wasn't he who had fixed Sarah, but rather, she had fixed him. However, during the course of their marriage, Sarah discovered that Jack's dedication to his work took up the majority of his time, placing an inevitable strain on their relationship. One night, Jack was kissed by another woman, Gabriela, whose father was Jack's patient, and who had just died during the surgery. When he admitted to Sarah about this kiss while promising her that he'll devote more time to their marriage, she, in turn, confessed that she had been seeing someone else and was leaving Jack. As their marriage finally dissolved, Jack increasingly became obsessed with discovering the identity of Sarah's lover to the point of mania and even suspected his own father of being Sarah's lover, the only evidence of this being that his phone number was on her cell phone's address book
Prize: Kate's affection, control of resources, leadership for the survivors, justice for Juliet's death, and later the opportunity to flee from the island.
Fuel: The two have constantly competed for Kate's attention. Their fight over Shannon's inhaler is a perfect example of this - Jack believed that Sawyer had Shannon's asthma medication. Sawyer didn't, but refused to say, even after Jack and Sayid tortured him. Instead, he used the possibility as a bargaining chip for a kiss from Kate ("Confidence Man"). Sawyer took much of the control over the Losties away from Jack with his con to get the guns. ("The Long Con") Kate herself exacerbated the situation by confessing mixed emotions to Sawyer and then kissing Jack. ("What Kate Did") Sawyer was also perturbed to learn that Kate and Jack had been "caught in a net." ("?") Later, during their captivity, Jack found a monitor showing an intimate moment between Kate and Sawyer. Instead of letting Sawyer die, Jack helped them escape in a selfless act ("I Do"). This rivalry was revisited after Sawyer was left stranded in the island on 1974 spending three years living with the Dharma Initiative. When Jack returned to the island from 2007, he and Sawyer disagreed on how to handle their return. This was complicated when Sayid was captured by the Dharma Initiative ("Namaste"). Later, Jack intended to detonate a hydrogen bomb in the island, and Sawyer disagreed with him not wanting to leave the island ("Follow the Leader"). Sawyer and Juliet eventually left in the submarine, but she convinced Sawyer of returning. The rivalry reached its climax when Sawyer confronted Jack and told him that his return had ruined his life on the island. After fighting, Juliet convinced Sawyer of letting him do what he wanted to do ("The Incident, Part 1"). Sawyer attacked Jack when the Jughead plan failed and then threatned to kill him if Juliet died. He later told Kate, after Juliet died that he wouldn't kill Jack cause he wanted him to suffer.("LA X, Part 2") Sawyer later puts his differences with Jack aside and allows him to partake in his plan to flee to Hydra Island on Desmond's Sailboat, and eventually from the island for good. However, Jack and Sawyer find themselves at odds once again when Jack expresses doubt in Sawyer's plan, believing that fleeing would not be a part of their destiny, and that they have a bigger purpose back on the island. Jack's desire to return to the island infuriates Sawyer and revives the enmity between the two men. Sawyer then orders Jack to leave the boat ("The Last Recruit"). The two are reunited shortly after Widmore's attempts to kill them forces a brief alliance between the survivors and The Man In Black. The two board the submarine with their fellow survivors, only to find that The Man in Black had planted a bomb that was timed for explosion. Jack tells Sawyer to have faith in his word that the bomb would not explode, but Sawyer agonizingly tells him that he does not and tries to diffuse the bomb. However, his attempt only accelerate the bomb's countdown. Jack and Sawyer narrowly escape with Hurley and Kate before the submarine explodes, but the rest of the survivors die onboard.("The Candidate")
Resolved: Yes. Jack comforts Sawyer in his guilt for his role in the deaths of Jin, Sun, and Sayid, telling him not to blame himself, but rather The Man in Black ("What They Died For"). When the two eventually part ways for good, Jack wishes Sawyer luck, while Sawyer thanks Jack "for everything," cementing the mutual respect that had eluded them for years. ("The End")
Origin: Jack helped break up a fight between Sayid and Sawyer.
Since Then: The survivors turned to Jack as a leader, even though Sayid first organized them and assigned tasks. Sayid soon concentrated more on escaping the island than settling into a society, with put him at odds with Jack's philosophy. The two also disagreed on how to deal with dead passengers -- Jack recommended burning the fuselage, but Sayid wanted to respect their religions -- and the two vied for a time for Kate's favor. But they worked together to torture and interrogate Sawyer, and Sayid then left the camp, ending the brief rivalry. When he returned, he told Jack what he'd learned of the Others. After Boone's death, Sayid uncovered the truth where Jack had failed and soon revealed to Jack the Hatch.
Some weeks later, Sayid tortured a prisoner against Jack's wishes, but Jack later agreed with Sayid's decision. When Sayid realized Michael was working with the Others, he offered to back Jack up by sea on a mission to save Walt. The mission failed, and Sayid had to later go to the Barracks free Jack. They returned with Juliet, and the camp began trusting Sayid over Jack, telling him rather than Jack of Naomi's arrival. Jack later regained the camp's trust, and he and Sayid devised a plan to defend the camp from Others. When the freighter's team arrived, Sayid negotiated a hostage exchange with Locke, claiming more capable of diplomacy then Jack. The two escaped the island shortly after and became members of the Oceanic 6.
Off-island, they initially kept in touch; Sayid attended Christian's service and both attended Hurley's birthday party. They later lost touch completely. But Hurley phoned Jack one day and delivered him Sayid's unconscious body. Both boarded Ajira 316, and both ended up on the island in the 1970s. Sayid shot an Other who threatened Jack, and the two together swam to recover Jughead. Sayid recommended they then disguise themselves as normal DHARMA personnel, and when one shot Sayid, Jack angrily killed two more. The two then traveled to 2007, and though Jack took Sayid to the Temple and attempted CPR, Sayid died, and Jack wept. Sayid returned to life hours later though, and both ended up in the Man in Black's camp after some days. They together freed their friends from Widmore's cages and boarded his submarine. Sayid then told Jack that he would be the next protector before sacrificing himself to save the rest from an explosion.
Origin: Sun crushed eucalyptus for Shannon, Jack's patient, helping her where he had failed.
Since Then: Sun assisted Jack in another medical operation, when he treated Boone. Sun realized that Jack was willfully ignoring Boone's internal injuries and tried to convince him to stop treating him in vain. Jack also noted Sun's garden with approval, and offered seeds for it, via Kate. When Jin left the Island on a raft, he advised Sun to stay with Jack for safety. Later, Sun consulted Jack when she thought herself pregnant. When Jack returned from his time with the Others, Sun welcomed him back to the beach with a hug. And when the camp split up, Sun chose to stay with Jack.
The two escaped the Island together. They lost touch - Jack did not come to visit Sun's daughter - but Sun visited Los Angeles some years later. Her surveillancve of Ben meant keeping tabs on Jack as well, and the two met again at the Longbeach Marina when Sun planned to kill Ben. They together visited Mrs. Hawking, and Sun showed up the next day for Ajira FLight 316, to Jack's surprise. When the plane landed on the Island, Jack had vanished, but the two reunited a week later. Sun lost the power speak, and Jack diagnosed her with aphasia, and she agreed to stay with him because she trusted him. Jack managed to free her from a cage shortly afterward, and his advice on Widmore's submarine almost saved her life. Jin though convinced Jack to leave the two of them to die together.
Origin: When the Others kidnapped Walt and Michael went missing, Jack confronted Tom, but Tom threatened Jack in return.
Since Then: Tom was one of several Others who hooded Jack and his friends on the docks during their kidnapping. The two got to know each other over the next days. Tom assisted in Ben's surgery, and Jack teased him by pointing out particularly bloody bits. Jack never revealed all he did during his next days in captivity, but he and Tom appear to have developed friendship, happily playing football together.
Origin: During his week aboard the Searcher, Jack learned Widmore sent the freighter that attacked the survivors.
Since Then: Jack had already decided that the Oceanic 6 had to lie to protect those who stayed behind. Once Jack learned of Widmore's involvement, this became a quest to avoid him, and Jack's last words to Desmond before they parted were a warning to flee from the man. Years later, Jack traveled to 1970 and met Widmore when he led the Others. Charles knocked Jack out with a rifle butt and held him captive till Jack convinced Eloise to follow Jack's plan.
Both ended up on the island in 2007, but though the periscope of Widmore's submarine caught sight of Jack on the beach, the two didn't cross paths.