As time dramatically ticks down, Peter, Olivia and Walter stop at nothing to save the universe from Observer rule. Walter enters the infamous deprivation tank in an attempt to uncover a key piece of information about the mysterious figure, Donald. Meanwhile, Captain Windmark sets out on a revealing mission of his own as long-standing questions are answered.
Elenco: Anna Torv , Jasika Nicole , Joshua Jackson , John Noble , Mark Valley , Blair Brown , Georgina Haig , Kirk Acevedo , Lance Reddick , Michael Cerveris , Seth Gabel .