Live Together, Die Alone, Part 1

A sailboat appears offshore. The camp can't believe their eyes. On board: Desmond. Drunk. He left weeks ago. He sailed in a straight line. And he came back to the same point. Impossible to leave the island.

Flashback: Desmond in prison. Then free. Then in Scotland. He loves Penny Widmore. Penny's father considers him unworthy. Desmond wants to prove his worth. He enters a sailboat race around the world. He crashes on the island. A man in the hatch welcomes him. Kelvin. He teaches him the protocol. The button. The code.

Kelvin dies. An accident. Desmond is alone. He doesn't push the button in time. The bunker shakes. The electromagnetic energy explodes. And a plane breaks apart in the sky. Oceanic Flight 815. Desmond understands: it's him. It's his fault.