George refuses to allow Jack to assist in Nina's interrogation. Jack resorts to blackmail to change George's mind. Palmer and Stanton meet with a Middle Eastern ambassador who may be in league with Second Wave. Tony visits the Warner home and questions Reza about his possible connection with Syed Ali.
Jack and Chase track down the last vial and Chase makes an incredible sacrifice. Gael's devastated wife visits CTU and seeks vengeance on Saunders. President Palmer makes an unexpected announcement after Sherry's death. The day's events take a toll on Jack.
Jack successfully rescues Secretary Heller and Audrey. CTU realizes that the train bombing was a cover up for a much larger attack. Dina's commitment to her cause is tested when Navi reveals his plans for Behrooz.
Jack meets with Mike Novick in hopes of gathering evidence against Cummings. Martha begs Aaron Pierce for help while Walt thinks that he is forcing Logan into aiding him with his complicity with the terrorists. Buchanan butts heads with Lynn McGill over a decision to violate the President's orders, while the Russian separatists attempt to escape with the nerve gas.
When threatening the Prime Minister's security guard doesn't work, Jack uses the ventilation system to smoke the couple out of their safe room. Henry Taylor discovers that his primary Secret Service guard is involved with the conspiracy. Renee gets captured while searching for Bauer and Emerson orders Jack to kill and bury her.