Summary and Spoilers
Desmond has just been brought out of sedation by Whidmore’s versatile henchwoman Zoe (engineer, gunfighter, nurse). Whidmore tells him that he was shot by Ben Linus. Whidmore also tells him that Penny and his child are safe. Oh, and one more thing: Whidmore tells him that he is back on the island. At this, Desmond begins beating Whidmore with an IV stand. Desmond is restrained and brought, along with Jin, to the generator room, where, after at least one Whidmore henchman dies, a test will be performed to see if Desmond can survive a catastrophic electromagnetic event. Desmond is locked in a room with a chair and two huge magnets, and is blasted from the island to the alternative universe. At an LAX baggage carousel, he meets other member of flight 815 (Hugo and Claire). He is chauffeured to Whidmore’s office, where he and Charles have a healthy working relationship brimming with mutual respect. Charles even breaks out the 60 year old Scotch (the significance of this will not be lost on loyal viewers). Whidmore asks a favor of trustworthy Hume: babysit a junkie base guitarist whom his wife and son want for a charity event. That druggie is Charlie.
Desmond meets Charlie at the courthouse. Charlie immediately ignores him and walks through traffic to get to a bar. Although it appears that Desmond is a success and Charlie a failure, Charlie begins to whittle away at Desmond’s hollow, loveless façade. Charlie breaks through by steering the car into the ocean. Desmond escapes but not before Charlie triggers memories of what has happened before – of Charlie’s previous drowning with the message "Not Penny’s Boat" written on his hand. Subsequently, Desmond receives more flashbacks while undergoing an MRI. Now he remembers Penny and his son. He presses the panic button, leaves the MRI, and goes in search of Charlie. Turned down by the nurse at the desk, he sees and asks Jack, but before Jack can answer, Charlie goes sprinting by. Desmond takes off in pursuit, then catches and confronts him. Charlie suggests that he forget about the concert and instead try to find Penny. Whidmore isn’t as amenable to this strategy and shows little compassion to Desmond, even though he almost died. Whidmore tells Desmond to deliver the message of the missing base player directly to Mrs. Whidmore (who just happens to be the woman we used to know as Eloise Hawking). Mrs. Whidmore is surprisingly forgiving about Desmond’s inability to deliver Charlie, but her mood changes when she overhears Desmond trying to find out more about someone named ‘Penny’. Mrs. Whidmore pulls Desmond aside and tells him to accept his life and stop searching for other things. It’s obvious that she is aware of the alternative timeline. She tells Desmond he is not yet ready to know these things.
As Desmond is just about to drive away, Daniel Whidmore (formerly known as Daniel Faraday) pokes his head into the limo and says they need to talk. Daniel tells Desmond that although he is a musician, he recently started scribbling complicated formulas using quantum mechanics that even he does not understand. Daniel believes in another life that he lived as a physicist, and that perhaps Penny is part of Desmond in this other life. And Daniel also tells Desmond where and when to find Penny – who just happens to be his half-sister.
At a stadium just like the one where Desmond met Jack long ago, Desmond meets Penny and says hello. They shake hands…and Desmond reawakens on the island, calm and ready to fulfill his role for Whidmore. As he accompanies a small group of people to his next assignment, Sayid appears and knocks most of them out. He tells Desmond that they are dangerous. Desmond calmly agrees and also agrees to go with Sayid.
Desmond returns to the stadium and Penny, where he had passed out after shaking her hand. She’s sweaty and he just fainted, and she agrees to meet him for coffee. Back at the limo, Desmond asks driver George to get him the manifest/passenger list from flight 815, so he can "…show them something."
"That man is the only person I’m aware of in the world who has survived a catastrophic electromagnetic event. I need to know that he can do it again – or we all die."
- Whidmore to Jin
Desmond: I don’t know anything about this woman. I don’t know – I don’t where she’s – I don’t even know if she exists. She is…she’s an idea.
Daniel: No, Mr. Hume. She’s my half-sister. And I can tell exactly where and when you can find her.
Desmond: You told me you brought me here to the island to do something very important.
Desmond: When do we start?