An unprecedented emergency sends Fairbanks into lockdown. Frank gathers every resource available to mount a full-scale response.

Luke tries to get back home as the manhunt for Havlock intensifies. Frank weighs whether he should give in to a set of demands.

Sarah's disappearance adds urgency to Frank's search. Havlock's master plan takes an unexpected turn, increasing the number of hostages.

A state trooper goes missing, widening Frank's investigation. Armed locals join the manhunt. Sarah grows concerned over Luke's whereabouts.

Frank focuses on tracking down Luke. The CIA's involvement ramps up as Havlock's plan enters a new phase.

Fairbanks is hit with a mass power outage. Sarah spots someone suspicious in the ER. Sidney tries to get control of a key piece of evidence.

A mysterious new suspect is interrogated. Frank's secret comes to light. Havlock works on retrieving the contents of his hard drive.

Sidney learns about her father's past, the Atwater Protocol, and the classified intel in Archive 6.