Contains spoilers for this episode and earlier episodes.
Jack travels with Eddie Grant's crew toward CTU, where they intend to plant explosives under cover of telephone repairs. With the building's lines disrupted, Jack reaches presidential aide Lynne Kresge and warns her of the attack. Eric Rayburn blocks an immediate evacuation because he fears exposing Jack's cover and losing the lead to the nuclear bomb. He instead orders CTU to send its investigation files to NSA servers, leaving Tony and Michelle questioning the unexplained deadline.
George Mason follows a police lead to a warehouse, where a shootout releases radioactive material. He orders a quarantine after seeing the warning sign, but has already breathed the contaminated air. At the Warner house, Ralph Burton tells Kate that Reza's passport information confirms contact with Syed Ali. He has alerted Homeland Security and urges her to keep the discovery private. Kim finds Megan and takes her by bus toward CTU, believing her father's workplace offers protection.
Inside CTU's garage, Jack frees the captive telephone technician and gives him a written warning for Tony. He then injures himself to disguise the escape and leaves with Eddie. The warning reaches CTU shortly before Palmer learns what Rayburn withheld and orders an evacuation. Kim and Megan, who have come seeking safety, join the rush to escape. The charges explode before everyone can get out, wrecking the building. Away from CTU, Mason is told that his radiation exposure is fatal.