A camera surveillling an Iraqi, Ismat Zahad, stops working. Bryan gets a text about a major alert and tells Asha to stay at his apartment. Asha figures out Bryan is some kind of covert agent. Christina tells her unit that an attack is imminent. Ismat has donned an explosive vest. Christina and Bryan go to Ismat's home. His son Amir disappears and grabs a cell phone from a tree, then runs, with Bryan in pursuit, eventually catching him. A video on the phone shows Ismat being abducted in the background. A follow-up exam reveals a grape-sized mass in Christina's brain. Riley tracks a rental car also seen in the video to Arlington National Cemetery. The captured suspect is FBI Special Agent Mike Gilroy. Rem and Scott go to pick up Reynolds, a serial killer that Gilroy captured, and briefly dump him unshackled in the interrogation room with a shackled Gilroy before hauling him away Reynolds. Gilroy admits to abducting Ismat, but has no further details. Riley gets a call with Ismat's location, four blocks from the Capitol. Bryan finds Ismat in the men's room, tied up and wearing a suicide vest. A phone call comes in, demanding Gilroy be delivered to an address or the bomb will be set off. Bryan refuses to leave. Bryan tries to get Ismat to somewhere in the cafe where there is no cell signal. The team surrounds the exchange site. Bryan drives Ismat into the basement of a parking garage, which shortly kills the signal. Bryan and Ismat go underwater, which fries the timer, and the team kills the men waiting to make the exchange. Riley traces Gilroy's records back to Bert Guiggey, Chief of Staff for the Secretary of Defense. Christina plans to meet with Guiggey, but has Bryan lined up to kill him if necessary. Bryan shoots both Guiggey and his backup. Christina goes to check in on Harry Ward and asks him to be her emergency contact.