- For other uses of "Zack" or "Zach", see Zack (disambiguation).
Zack was a tail section survivor of Oceanic Flight 815. He was a young boy, traveling with his sister Emma to meet their mother in Los Angeles. Zack was one of only three children to have survived the crash of Oceanic Flight 815. Zack and his sister were kidnapped by the Others on their twelfth night on the Island. During their time with the Others, Cindy acted as their primary caretaker.
On the Island
Days 1–12 (Season 2)
Zack watches as Eko drags Emma out of the ocean. ("The Other 48 Days")
Seconds after the tail crashed into the ocean, Mr. Eko carried Zack to shore. Zack called out for his sister and pointed to her body floating in the water. Eko pulled her to safety and Zack rushed over to her. He dropped her teddy bear next to her before Eko led him away. Ana Lucia began performing CPR and soon revived her. Soon after the crash, Eko asked Cindy if she could look after Zack and Emma while he dragged the dead bodies out of the ocean.
That night the Others invaded the camp and kidnapped three of the survivors. In the morning, the group discussed whether or not they should stay on the beach. Libby held Zack and Emma during the discussion. Nathan tried to get the group to stay on the beach to continue feeding the signal fire, noting the fact that there were kids and injured people who would be difficult to move, and questioning how they would be rescued if they did not keep the signal fire going. Cindy backed up Nathan, informing the tail section survivors that they were a thousand miles off course when the plane crashed.
Ana Lucia and Libby became maternal figures to both Zack and Emma. The children were at Donald's funeral, both hugging Ana Lucia and looking sad. On Day 11, Ana Lucia looked on as Zack and Emma had a small disagreement while playing. However, the next day he and his sister were among the nine tail section survivors kidnapped by a mission of the Others. ("The Other 48 Days")
Juliet assisted in caring for Zack and Emma, who continued to ask about their mother in Los Angeles weeks after the crash. Ben assured Juliet that they would stop asking in time. Juliet reminded Ben that Zack and Emma were children, to which Ben retorted that the two were on the list. ("The Other Woman")
Days 74–86 (Season 3)
Zack gives Jack a confused look. ("Stranger in a Strange Land")
While Jack was imprisoned in the cages at the Hydra station, Zack, holding the teddy bear, approached him, along with his sister Emma and fellow crash survivor Cindy. After Jack yelled at Cindy, they turned to leave and Zack handed his sister the teddy bear. He remained behind for a moment and gave Jack a confused look. ("Stranger in a Strange Land") When Kate found Jack at the Barracks, Jack confirmed to Kate that they were safe. ("The Man from Tallahassee")
2007 (Season 6)
Cindy, Zack, and Emma listen to Sayid's speech. ("Sundown")
Zack and Emma lived with the Others at the Temple in 2007. Cindy asked them to give food to the survivors shortly after Sayid's apparent death. ("LA X, Part 2") Later that same day, Zack, Emma and Cindy listened to Sayid's speech and grew concerned when they heard what he had to say. They decided to leave the Temple along with fifteen or so fellow Others. Zack was seen holding his teddy bear during the exodus. ("Sundown")
Zack, Emma and Cindy followed the Man in Black to Claire's hut. Once there, Cindy inquired what happened to the people who did not leave the Temple. The Man in Black responded that they are all dead. This seemed to disturb Zack, and Emma and Cindy comforted him as he began to cry. The Man in Black walked up to Zack and told him that he knows what happened back at the Temple was really scary, but it's now over. He then promised the children he would take care of them. The group soon left Claire's hut and Zack and Emma were notably directly behind the Man in Black on the trek. Zack and Emma arrived with the rest of the group at a clearing, where the Man in Black declared they would be staying for a few days. ("Recon")
- In "...And Found", Eko and Jin see some people, possibly Others, walk past them in the jungle. One of the group appears to be a child, and is dragging with him a teddy bear tied to some rope. The bear resembles Zack's.
- Zack is one of the eight recurring characters whose last names we don't know. The other seven are Phil, Bram, Omar, Emma, Jason, Neil and Zoe.
- In every episode that Zack and Emma have been in, Cindy has appeared as well.
- In "LA X, Part 2-Enhanced", when Zack and Emma appeared on screen, an enhanced caption stated that their parents died in the crash of Oceanic 815. According to Emma, the children's mother was supposed to meet them in Los Angeles, ("The Other 48 Days") and their father was never mentioned. The enhanced episodes were stated by the producers to be non-canon.
- On the main screen of Disc 6 of the Season 3 DVD Box Set, Zack and Emma can clearly be seen walking around the ruins along with their teddy bear and an unknown female.
- The spelling of this character's name is unclear. It has been spelled both "Zach" and "Zack" in various press releases and official ABC documents. The Lost Encyclopedia spells it as "Zack".
- Of all the main characters, Zack has only met Ana Lucia, Libby, Eko, Bernard, Juliet, Ben, Jack, Locke, Sayid, Kate, Jin, Miles, and the Man in Black.
- In "The Other 48 Days", there is a scene in which Zack and Emma are fighting over a stick. In real life, Mickey Graue found this stick and Kiersten Havelock was fighting him for it. The cameraman filmed their fight and later it was used in the episode. [source needed]
- Zack and Emma appeared in four episodes in Season 6, more than in all other seasons combined (three).
- Zack is one of the few Oceanic Flight 815 survivors alive at the end of the series, along with his sister Emma, Hurley, Kate, Sawyer, Claire, Aaron, Walt, Cindy, Rose, Bernard and Vincent.