7. Five-Twenty-Ten

Complete story — includes the ending

Another tape leads the Fringe team to the ruins of a lab where two Observer-made beacons (seen in a previous episode ) are kept in William Bell's private storage, only accessible with Bell's handprint. The beacons can locate a point in space and time. Peter uses his new Observer-like abilities to find Bell's storage in the rubble; Nina Sharp, who now works for the Ministry of Science, provides them with an Observer device that evaporates the rubble, and Walter uses Bell's hand that he obtained in Letters of Transit to retrieve the beacons. Meanwhile, Peter's new abilities allow him to predict the movements of two of Windmark's lieutenants, enabling him to replace one lieutenant's briefcase with one that contains the toxin from the first Fringe case. The toxin is released at a meeting, killing at least three Observers. Olivia worries about Peter, who has started to change due to the Observer implant. She discovers his prediction of Windmark's trajectory, and he tells her about the implant and his plan to kill Windmark and thus avenge Etta.