FLASHBACK: Locke is working in a toy store. He is setting up a game of Mousetrap and a young boy asks to see how it works. He notices a woman that is standing off to the side. She is staring at him. Locke approaches her but she only asks for a football. Locke tells her what aisle they are in and goes back to his work.
On the island, Locke and Boone finish building the trebuchet so they can use it to open the hatch. Boone wonders about Locke's life before the crash. Locke says that it would bore him. Locke then uses the trebuchet to try to open the hatch. It slams down on the hatch and doesn't even leave a dent. The trebuchet itself shatters and falls apart. Boone points out that there is shrapnel sticking out of Locke's leg. Locke can't feel the pain and doesn't even notice it until he pulls it out of his leg. That night, Locke is sitting by the campfire. He decides to test his reflexes by taking a branch from the fire and pressing against the bottom of his foot. He feels nothing and is scared that he may become paralyzed again.
The next day, Locke tries to convince Boone to help him rebuild the trebuchet. Boone doesn't like the idea anymore. He's not sure what they should do. Locke says the island will send them a message and tell them what it is they are supposed to do. Boone starts to doubt Locke. At the same time, Locke is starting to have trouble walking.
FLASHBACK: Locke is in the toy store parking lot. He sees the woman again as he is about to leave. He chases after her. When he finally catches up to her and asks her why she is following him, she says "I'm your mother."
Locke is now sitting with his mother at a diner. She tells him that their meeting is a sign of great things and destiny. Locke asks about his father but she tells him that he doesn't have a father. "You were immaculately conceived." Locke is shocked by her comments.
On the island, Sawyer asks Sun which leaves he can use to cure a headache. Kate overhears and talks to Sun once Sawyer leaves. Sun says that Sawyer has been having headaches that aspirin can't cure. Kate goes and tells Jack about Sawyer's condition. Jack says he would help, but he knows Sawyer won't let him.
Boone finds Locke at the hatch. He tells him that he is giving up. He doesn't think they can open the hatch. "The island will send us a sign..." Locke looks overhead and sees a plane fly by. When Locke looks back at Boone, he sees him covered in blood. Boone is chanting the phrase "Teresa falls up the stairs, Teresa falls down the stairs..." Locke is confused and then sees his mother pointing in the direction of the plane. Then Locke looks down and sees that he is paralyzed and wheelchair bound again. Suddenly Locke awakes from his sleep. He gets up and wakes Boone to head off into the jungle.
FLASHBACK: Locke is meeting with a private investigator. He wants to know about the woman who claims to be his mother. It is confirmed that she is Emily Annabelle Locke, his mother. He tells Locke that she has schizophrenia. Locke then asks about his father. "Your mother sought you out, so she's fair game. This guy may not even know you exist." Locke wants to know anyways. The investigator gives him a red folder with information about his father.
Locke pulls up to a gate and asks a guard if he can see Mr. Cooper and explains that he is his son. He waits in his father's den and looks at photographs. His father comes in and offers him a drink. Cooper says that he didn't know he existed because Emily said she wasn't going to have the baby. He also says that he has no family. He asks Locke to go hunting with him the next weekend.
At the hatch, Locke tells Boone about his dream. He thinks the plane is the sign they've been waiting for. Boone thinks Locke has lost it. This prompts Locke to ask "Who is Teresa?" Boone says it was his nanny that he used to torture by calling her up and down the stairs over the intercom. He says that one day she missed a step and fell. Boone tries to figure out if he ever mentioned this to Locke before. Either that or Locke's dream holds the truth.
Jack goes to check on the raft building. He sees Sawyer sitting against a tree with a wet cloth on his forehead. He goes and asks him about the headaches. Sawyer isn't happy that Kate told him and brushes him off. Jack goes to leave, but Sawyer starts talking. He is genuinely concerned that he could have a brain tumor, like the one that killed his uncle. Jack says he wants to run a couple tests on him at the caves. Sawyer says he can't because "my insurance ran out."
Locke and Boone are trudging through the jungle when Locke's legs give out on him and he falls. Boone wants to know what's wrong. Locke says he is fine. He looks up and sees a decomposed body fall from the tree above them. They figure out that it was a priest, by his clothes. However, they find a gun in his pocket. What priest carries a gun?
FLASHBACK: Locke goes to the estate again. He is going hunting with his father. He gets there early and finds his father hooked up to a kidney dialysis machine. His father's kidney is failing and since he is older he is near the bottom of the list for donors. He didn't tell Locke because he didn't want it to ruin their time together.
On the beach, Sawyer's headaches get worse with every little noise around him. Kate tells him that he should go see Jack. So he does. Jack runs a few tests and then asks him a series of questions. They start out as normal questions then they get more ridiculous. Jack asks him if he has ever had an STD, to which Sawyer says yes. After asking when the last time it flamed up was, Sawyer gets mad and storms out of the caves. Kate watched all of this. She asks Jack is it was necessary to have fun with Sawyer like that. Jack laughs and says that Sawyer is fine - he needs glasses.
In the jungle, Locke and Boone keep looking for the plane. Locke is still having trouble walking. He blames the shrapnel wound. Boone points out that he is limping with his left leg right now and the shrapnel hit him in the right leg. He thinks they should head back and find Jack. Locke demands they go on and then collapses again. Locke tells Boone that he used to be in a wheelchair and that the island made him whole again. The plane is something they are meant to find. He asks Boone to help him up.
FLASHBACK: Locke is walking through a field while hunting with his father. Locke shoots his first dove. His father congratulates him and says that he is happy they can be together, while there is still time.
In the jungle, Boone carries Locke with him. They stop to rest when Locke looks up and finds a yellow Beechcraft - the same plane from his dream. It is hanging in the tree canopy. Locke says he can't climb but that Boone is going to have to go up and see what is inside.
FLASHBACK: Locke is lying in a surgical bed next to his father. He is going to donate his kidney for his father's sake. His father says "I'll see you on the other side..."
On the beach, Jack brings Sawyer a box full of glasses and says that he needs them since he has been reading so much lately. He tries on a bunch of pairs but none seem to work that well. Sayid takes the two pairs that work best and fuses one eye from each together. They don't look good, but they work. Jack says it's not a fashion show and leaves Sawyer to check out his new look in the mirror.
In the jungle, Boone climbs the massive tree and gets inside the Beechcraft. Locke looks on helplessly from the ground. Boone finds a map and another body. He jumps back as he finds the body and it causes the plane to lurch. Locke calls to Boone to tell him that the plane is very unsteady. Boone is too curious and won't leave. He find statues of the Virgin Mary. He throws one down to Locke and it breaks and reveals 5 bags of heroin were inside. Boone is angry and says this wasn't a sign after all. Then he finds a radio on the dash. He turns it on and hears static. He uses it and makes mayday calls. He hears a muffled voice and attempts to communicate with it until the plane lurches again. Locke yells to Boone to get out but it's too late. The plane slides through the canopy, flips over and crashes to the ground. Locke drags himself over to the plane as his legs begin to come back to him. He finds that Boone is extremely wounded inside. Locke pulls him out, throws him over his shoulder and runs back to camp.
At the caves, Kate thanks Jack for helping Sawyer. Locke comes rushing in with Boone. He tells Jack that it was an accident - that Boone fell off a cliff while they were hunting. Jack sends Kate for towels and water. He turns back for supplies and then asks Locke for more details. He turns to look for Locke and finds that he is gone.
FLASHBACK: Locke wakes up in the hospital and the bed next to him is empty. The nurse tells him that his father checked out already. His mother appears in the doorway and starts to apologize. She says that she needed money and went to Cooper. He told her to find Locke. Locke realizes that it was all a plan to trick him into donating his kidney to his father. Locke gets up from the bed and rips the IV from his arm. He drives to Cooper's estate but the guard, who used to be friendly, is now cold and turns him away. Locke gets out of the car and goes to the gate. He stares into the camera. The guard makes him get into his car and leave. He only drives a few blocks before pulling over and breaking down into tears.
In the jungle, Locke is bent over and kneeling on the hatch. He yells out in pain, feeling betrayed: "I've done everything you've asked me to do! Why?" He bangs on the hatch in frustration. Suddenly a light comes on from inside the hatch....