Spoilers for this episode.
Jack catches Navarro after the fugitive drops the override device for Cross at Liverpool Street station. Cross abandons the promised escape arrangements and leaves Navarro to arrest, then departs with Chloe and the device. Ritter takes command of the CIA station. Jordan's files reveal that Navarro framed Kate's husband, whose suicide means the discovery cannot bring him home. Navarro tries to bargain for immunity by withholding the code needed to track the stolen device.
Jack's violent interrogation fails to break Navarro's demand, so he and Kate stage a confrontation in the infirmary. Kate threatens to kill Navarro while Jack appears to restrain her, frightening him into revealing the tracking code. Chloe meanwhile attempts to leave Cross with the device, but he forces her back into his car at gunpoint. They arrive at Open Cell's new base and find the other hackers murdered. Cheng Zhi is waiting with armed men and demands access to the override technology.
Cheng compels Chloe to work after Cross cannot reverse Yates' modifications. Her attempt to sabotage the device is detected. Cross admits that Chloe's husband and son died in a genuine accident before Cheng kills him. The device sends a false order to an American submarine, causing it to attack a Chinese aircraft carrier. Jack and Kate race toward the tracked location, but Russian gunmen ram their car and open fire. Mark supplied the information used to locate Jack, and the agents are pinned down as the international crisis begins.