This is the penultimate episode of the third season of Fringe. It will be followed by the season finale, "The Day We Died."

The mystery of Sam Weiss was unraveled. He is the last of a long generation and possesses unknown amounts of knowledge passed down through them.

The world continues to react to the machine in what seem to be dry electrical storms.

Walter, Astrid and Olivia work diligently to find a way to get Peter inside the machine to stop the end of the world.

Sam takes Olivia to a "key" that shows how to interact with the machine. It is a drawing revealing Olivia's place in the equation.

Peter awakens and together, he and Olivia attempt to adjust the course of the future through the machine.