After the extraordinary turn of events that shockingly left an imprisoned Olivia "over there," she fights to find her way home. Meanwhile, Peter and Walter try to move on with their lives unknowingly alongside alternate Olivia.

The alternate universe Fringe Division investigates a shocking breach of security when a twin frees his brother from a quarantined Amber area. As the team sets out to crack this sophisticated case, Walternate experiments over there more with Olivia as she reenters the tank. Meanwhile, visions of Peter continue to haunt Olivia about returning to the “other side”.

The intensity of life “over there” accelerates as Olivia finds herself in mortal danger.