Jack goes undercover to retrieve deadly nuclear materials. Meanwhile, it's a political pressure cooker when President Taylor's goodwill comes under question.
President Taylor pressurises CTU and Jack's plan has operatives panicked. Meanwhile, as the looming threat intensifies, events take a turn for the worse.
Doggett comes upon an old case that Mulder kept secret from Scully, and he follows up the investigation hoping to find a possible connection to Mulder's disappearance.