This week's Lost took a break from wrestling with good and evil and followed the alternate time lines of Desmond, Charlie, and Daniel. In contrast with real time, alternate timeline Desmond is Charles Widmore's second in command. But back on the island in real time, Widmore kidnaps Desmond, subjects him to a shocking burst of electromagnetism, and then tells him he doesn't know anything about sacrifice.
Sacrifice becomes our major theme in this episode and provides a connection to the other characters' experiences in the alternate time line. Desmond just lays it out more clearly for us. In the original timeline, he's a devoted husband and father, sure only of his wife Penny's love for him, and desperately seeking her father Widmore's approval. In the alternate timeline, he has the approval. Widmore feeds him 60-year old whiskey and tells him: "You really have the life, son. No family. No commitments. Free of attachments."
Yet Desmond senses there is more and his interaction with Charlie, still a drug addicted musician, and later Daniel begin to link the two timelines. Charlie drives Desmond's car off a pier in the Los Angeles port and the epic drowning scene that ensues triggers a vision for Desmond of Charlie drowning in the Looking Glass station on the island, in the original timeline. Charlie's hand, pressed to the window, reads, for an instant, "NOT PENNYS BOAT" just like Season 3.
After speaking with a groggy Daniel (poor guy is the musician he always wanted to be, yet dreams about physics and his "true love") about a catastrophe "changing things", Desmond starts to get it. He finds Penny doing a tour de stade (man, Lost characters sure like to run up and down stairs), asks her on a date, and then tells his Widmore-provided driver, George, to get him a list of the passenger names of Flight 815 because he "just needs to show them something."