The episode begins with Desmond being taken to the hospital after Ben Linus shot him. Eloise Hawking is there and says that it is her son’s fault that Desmond was shot.
Then, thirty years earlier, Daniel Faraday arrives on the island then comes to see Jack. Dan tells Jack that his mother was wrong, it wasn’t his destiny to come there, and in fact he doesn’t belong there at all.
In a flashback of Dan’s childhood, we see him playing the piano. His mother tells him that destiny means that if someone has a special gift, it must be nurtured. She asks him how many beats the metronome has ticked since he started playing, and he knows the answer. She says that his mind is his gift and he must focus on science and mathematics. He says he will make time for both music and science, but she insists that he can’t make time, although she wishes that he could.
Then at Dan’s graduation, as the youngest doctor to graduate from Oxford, his mother comes to congratulate him. He talks about how she kept pushing him, and asks when it will be enough. She gives him a gift, a notebook, in which she has written in the front that she will always love him.
Just after seeing the discovery of Oceanic 815, Daniel is saddened, presumably because his mind is unstuck in time. Charles Widmore comes to see him, admitting that he faked the plane in the ocean and that the survivors are alive on a very special island, and that he wants to send him there. He says the island will heal his mind and memory, as well as showing him amazing things. He says that he and his mother are old friends. Later, we see Dan struggling to remember the piece we heard him playing perfectly on the piano earlier. His mother tells him it is very important that he say yes to Mr. Widmore. She struggles to tell him to go, saying that it will make her proud of him. The mixed emotions are clear in her facial expressions.
In the Dharma Initiative era, Dan goes to talk to Dr. Chang – in a different perspective on the scene that started the season. He asks him to evacuate the island, talking about the energy at the Orchid site which harmed someone, and how the work at the Swan station will cause something similar but much worse. He tells him that Miles is Dr. Chang’s son, but Chang is not persuaded. Dan then tells the Oceanic 815 folks that he needs to find the hostiles, because one of them is his mother, and she is the only one who can help get them back where they belong. Dan, Jack, and Kate go to look for them. The rest plan to head for the beach. On his way, Dan stops to talk to Charlotte. He tells her that she and her mommy should get on the submarine when Dr. Chang evacuates people. He says that he tried to avoid telling her this, because he didn’t think he could change things – but maybe he can.
Radzinsky finds Phil tied up in James and Juliette’s home.
Dan tells Jack that in about four hours, the digging at the Swan is going to unleash catastrophic energy, which will then have to be cemented in like Chernobyl, eventually leading to the crash of Oceanic 815, and the entire chain of events that follows from it. But we can change this. He says that he studied relativistic physics all his life and was persuaded that the past could not be changed. But he focused on the constants, and not on the variables – people with free will who can change our destiny. He says he thinks he can destroy the energy under the Swan, preventing the crash of Oceanic 815, by detonating a hydrogen bomb.
At the end of the episode, we see Eloise Hawking talking to Penny. She says that, for the first time in a long time, she doesn’t know what’s going to happen next. Desmond turns out to be fine. On her way out of the hospital, Charles Widmore asks Eloise how Desmond is. We learn that Dan is his son as well as her’s. And she rebukes him for talking about sacrifice, given that she just sent her son to the island knowing full well what would happen to him.
Dan walks into the camp with a gun demanding to speak to Eloise. She shoots him, and before he dies, Dan says, “You knew this would happen, and you sent me anyway.” When she asks who he is, he says that he is her son, and then he dies.
This is a fascinating twist, that ties up in a huge knot the major characters who’ve been at work behind the scenes. When Eloise Hawking and Charles Widmore worked to send Dan to the island, knowing he would die and that he was their son, did they do this because they believed the past cannot be changed? Or did they do it hoping that the past might be changed, with that being their aim in driving him on and funding him in his research in physics?