A bloodied Boone appears in Locke's dream in "Deus Ex Machina".
While excavating the hatch, Locke sees a small aircraft crashing into the jungle in the episode "Deus Ex Machina". This appears to be a dream, which concludes with Boone covered in blood, repeating the phrase "Theresa falls up the stairs; Theresa falls down the stairs." Earlier on in the dream, Locke had eerily seen his mother in the jungle, staring at the sky and he was suddenly confined to a wheelchair. This was in keeping with the flashback of the episode. Later, when describing the vision he had, he asks Boone, "Who is Theresa?" and is told that she was his childhood nanny whom he believes he caused to fall to her death in his family home. Locke insists that they have to locate the plane, which is eventually found hanging in the trees.
Locke/Eko scaling the ledge.
Locke dreams that he is Mr. Eko (confirmed that it is his point of view when Locke wakes up later and says he "wasn't himself", and the fact that he still has his blast door injury limp in the dream). He sees Eko's brother, Yemi, who was in the crash of the Beechcraft, crouching in the plants. Yemi leads him up the edge of the cliff that the small plane had originally rested on. Locke/Eko climbs up the ledge using the axe. Once he reaches the top, Yemi is suddenly sitting in a wheelchair and says "Wake up, John" which scares Locke/Eko, who plummets off the edge, at which point Locke wakes up. After telling Eko of the dream, Eko scales the cliff and sees a question mark, which leads him and Locke down into The Pearl Station, which is situated under the Beechcraft.
Boone and Locke at the airport.
In "Further Instructions" Locke enters a sweat lodge, ingests a drug, and experiences a vision. In his vision, he is guided by Boone through the Sydney Airport and instructed to save Eko. In the sweat lodge, Boone first greets Locke, who realizes he is paralyzed again. When Locke tries to communicate, "Boone" tells him it's "okay, I was the sacrifice the island demanded," and then "Don't worry; you'll speak when you have something worth saying." Boone then shows Locke his old wheelchair, noting, "John, you're going to need that." Locke then finds himself in his wheelchair being guided by Boone through the Sydney Airport, where he sees the other characters on the Island grouped as they are in current time, in contexts that parallel their true situations. With each group, Boone comments on their relation to Locke's current quest to "make things right."
Kate and Sawyer waiting in line in Locke's vision.
First, Claire, Charlie, and Aaron are together in line looking happy, as Boone comments, "Not them, they'll be fine... for a while." Jin and Sun are together mildly arguing as Sayid taps Jin on the back, while Boone says reassuringly, "I think Sayid's got it." Hurley is dressed as a ticket agent, and looks happy as he sits and types the Numbers into the airline computer when Boone says, "Not Hurley." Desmond is enjoying himself, dressed as a captain, arm in arm with three beautiful flight attendants, as he descends an escalator, while Boone says, "Forget it. He's helping himself." Sawyer and Kate are together in line smiling at each other, while nearby, Jack is alone and looks despondent as Ben is a TSA agent examining him with a security wand. Boone then comments, "There's nothing you can do for them... not yet. First, you have to clean up your own mess." Then, Locke is forced to ascend the escalator without his wheelchair crawling on his hands. When he reaches the top landing, discovers Eko's stick coated in blood. Boone, now also covered in blood, tells Locke: "Clean it up, John. They've got him. You don't have much time." John sees a polar bear roaring at him out of the fire as he returns to regular consciousness.
Of note: in the scene of Sawyer and Kate standing at the security line (run by Ben), he tells her, "Wipe the stars out of your eyes, sweetheart...watch and learn little lady." In the next episode, "Every Man for Himself", while devising his plan to shock Pickett with the fish biscuit dispenser, Sawyer says to Kate: "Watch and learn little lady...[explains the plan]... Wipe the stars out of your eyes, sweetheart..." Since this had not yet happened in the previous episode, and the two were on separate islands, it is regarded as a premonition.
Horace tells Locke that he must find him to find Jacob.
In the episode Cabin Fever, Locke awakens from his sleep to the sound of an axe. He follows it and finds a man in a DHARMA jumpsuit, with the logo of The Arrow on his suit, cutting down trees. Locke asks him who he is, and he informally answers that his name is Horace. He tells Locke that he is building a getaway for himself and his wife, and that he needs a break from the DHARMA Initiative. Seeing the confused look on Locke's face, Horace asks if he makes sense, to which Locke replies that he does not. Smiling, Horace turns to Locke, bleeding from his nose, and replies that it is probably because he's been dead for twelve years. John is told that he needs to find Horace in order to find Jacob. Strangely, Horace begins cutting down the same tree he just toppled, which has reappeared. Horace repeats several previous sentences, and cuts down the tree for a third time. John then awakens and later goes to the Mass Grave along with Ben and Hurley, and starts to dig through the many bodies of DHARMA workers, he then comes across the mummified remains of Horace. Locke searches Goodspeed's pockets and uncovers a map that says "Cabin", this gives him their heading towards the cabin.