Peter Woodward

When a Marine is found dead, Gibbs, Fornell and the team hit the open road to bust an illegal trucking operation.

When Piper switches powers with Phoebe, to allow her to see the vision of the utopian world, Zankou interferes, and causes their powers to be transferred to innocent bystanders, who run amok.

There's more than one Observer! When one of the series' mysterious Observers kidnaps a woman, the Fringe team is called in to investigate why. But while the course of their investigation not only reveals the private lives of the Observers, it also threatens to unearth Walter's clandestine involvement with them years before – a secret he's desperate to keep from his son, Peter. As destiny is irrevocably rewritten and time is running out, the renegade Observer asks for help from the unlikeliest of sources…Walter Bishop.

While explaining Peter's otherworldly origins to Olivia, Walter flashes back to 1985 and the mystery springs forward by revealing the past. Also, Peter's mother (guest star ORLA BRADY) is introduced - and details of the neighboring world reaffirm that there is definitely more than one of everything.

Farik sets the attack on Dodger Stadium in motion by triggering a Decoy explosion. In the midst of several fire trucks arriving on the scene, the Cell’s own emergency response vehicle escapes and slips by the FBI with deadly containers of toxic chemicals inside. Before leaving the warehouse Darwyn snags Ilea's ticket to the ballgame and places it inside his Quran as a clue for the FBI. Serxner realizes that the explosion was a decoy and raids the empty warehouse finding the baseball ticket. The FBI is now racing against the clock to intercept the Cell’s attack on the stadium.