LOST: It Wasn't Purgatory, Episode 19, Deus ex Machina

Events: Beginning with a flashback, the episode shows toy store associate John Locke (thinner and with dark hair) explaining the game "Mouse Trap" to a young customer and then quickly transitions to Locke and Boone on the island preparing a trebuchet to open the hatch. The trebuchet fails, Locke becomes upset, and Boone notices that a piece of metal has lodged into Locke's leg.


More flashbacks show the history between John and his birth parents, Emily Locke and Anthony Cooper. John purchases information on the two from a private investigator who cautions "this stuff isn't always meant to be," and "it probably won't have a happy ending." John seeks out Cooper, who is revealed to be in kidney failure and the two forge what John believes to be a father-son relationship which ends in John donating one of his kidneys. Cooper is not interested in keeping John in his life and cuts off all contact with him after the operation.

On the island, John fears his paralysis is returning but stubbornly insists on trying to open the hatch. He dreams of a small aircraft, Boone covered in blood reciting "Teresa falls up the stairs, Teresa falls down the stairs", Emily Locke pointing in the direction the aircraft flew, and of himself once again in a wheelchair. The next day he wakes Boone and they set out into the jungle to find the airplane, which has indeed crashed onto the island and is hanging off the side of a cliff. Boone climbs up to investigate while John waits on the ground below, unable to participate as both of his legs have failed. Boone discovers statues filled with heroin inside the plane and attempts to communicate through the plane's radio but the plane pitches off the cliff, seriously injuring Boone. John somehow musters the strength to carry Boone back to the cave but vanishes when Jack tries to get the details of the injuries. After returning to the hatch, beating upon it, and shouting out, "Why did you do this to me?" John
sees a light shine out from inside the hatch's
window.

We're the survivors of Oceanic Flight
815! 

Greater Meaning: There is a case being made for Locke not opening the hatch. The fact that it seems impossible to do so is only part of it, but the bigger and more personal worry is how Locke's own body is responding to his stubbornness. After the trebuchet fails, Locke is stabbed in his right leg by metal debris. The closer Locke and Boone get to the plane (which Locke assumes will hold some secret or tool to aid in the opening of the hatch), the worse Locke's condition gets with not just one but both legs affected. As the island seems to have healed Locke's paralysis it stands to reason that the island could also stop doing so as well, but why? The flashbacks show Locke refusing to listen to reason in regard to his parents (the investigator all but spelled it out for him) the same way Locke is refusing to be influenced by the systematic breakdown of his body as he insists they seek out the aircraft. As his interactions with Emily Locke led to heartbreak, his following of the airplane led to physical demise in both himself and Boone (which was foreshadowed in his dream of Emily pointing, Boone covered in blood, and his own position back in the wheelchair).

I've done everything you asked! 

Locke wants to believe he's doing the right thing, he has faith in what he's seeing, but he isn't interpreting things correctly and he's ignoring hard, logical facts. If the island cured him, why is it suddenly taking it all back? Locke has proven himself to be an able leader, skilled hunter, and quite intuitive when it comes to the island itself; what if the island is taking his legs away from him because he's simply on the wrong track? Why did he have the vision of the plane or Boone's experiences with his nanny falling down the stairs and how would he have known about either one of those two completely unrelated events? If something on the island planted these events into Locke's unconscious mind, why is another force on the island trying to keep him away from the very events these visions set in motion? Are there two forces at play in Locke's head or is he simply cracking up? Are all of the survivors subject to this kind of influence or only Locke? The title "Deus ex Machina" suggests the hand of God coming in to save everyone in the end with an unexpected resolution, but it remains to be seen what (if anything) was resolved or saved.

Further Questions: 

1. How did Locke become injured and require a wheelchair?
2. Did Locke and Anthony Cooper ever reconcile?
3. Did Emily Locke become part of Locke's life?
4. Are Locke's visions working against him?
5. Will Boone survive?
6. What is in the hatch, and will it ever be opened?
7. Who were the men dressed as priests?
8. Who was speaking on the radio to Boone?