Human beings are reduced to ash statues and Broyles realizes that the same person responsible murdered five other persons four years ago... a case that he never solved.

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.

Newton, concerned about the consequences of a distressing development involving a high-ranking official, is forced to call to action a sleeping shapeshifter. As Walter and the rest of the team gather evidence, they move the investigation to Massive Dynamic, where Olivia goes on high alert and Walter finds himself in a perilous situation.

The Fringe team is pushed to the breaking point as they desperately attempt to prevent a catastrophic event that threatens the lives of everyone.