16. Nothing as It Seems

Complete story — includes the ending

A passenger, Marshall Bowman, on a plane transforms into a strange beast, due to a "designer virus" with which he has been injected. Peter recognizes this as a case from his original timeline but in this timeline, Bowman never fully transformed on the plane, allowing it to land safely. However, while under investigation by the TSA, Bowman transformed and attacked the agents before dying. Meanwhile, Olivia, having accepted the replacement of her memories with those from Peter's original timeline, is determined to be unfit for field work because she can't remember her "real" past. Lincoln Lee is put in charge of the Fringe team. Peter uses his recollection of the Bowman case to lead the team to Daniel Hicks, who was to receive the designer virus before he too transformed. Hicks, now transformed, escapes. The team finds out that the Hicks creature is nocturnal and can fly. Lincoln leads the team to stop the creature along with a woman who was caring for it. The creature is killed, while the woman is unable to supply answers about where the designer virus originated from. Phillip Broyles tells Olivia that while she may be losing part of her memories, she is still an asset and is allowed back to active duty. The episode ends on a revelation of a container ship that contains a number of other transformed humans and other creatures at sea.