The Fringe Division visits the Massive Dynamic to see the Doomsday Machine and the presence of Peter collects the gadget. He is submitted to tests by Dr. James Falcon without wanting to. Walter requests that Nina discover William Bell's exploration since he needs to reestablish his cerebrum to expand his IQ and help Peter. Then Broyles offers admittance to the principle outline where the other Olivia's documents are to support the examination and they think there is a mole getting to the data. Before long they find that somebody is executing the shapeshifters. Who may be the executioner?