Sisko finds that Admiral Leyton and a group in Starfleet staged the crisis on Earth in an attempt to impose military rule.
In the second half of a two-part story, Earth sits under martial law over fears of Changeling infiltration. Sisko suspects the crisis is being manipulated, and with help from Odo and Nog's contacts among the elite Red Squad cadets he gathers evidence that Admiral Leyton is preparing a coup. President Jaresh-Inyo wants more proof. A Changeling disguised as O'Brien taunts Sisko by revealing there are only four of its kind on Earth, a tiny number causing enormous panic.
Kira finds that a station officer working for Leyton has faked wormhole openings to suggest a cloaked fleet, but Leyton has Sisko framed as a Changeling and jailed until Odo frees him. As the Defiant brings the officer to Earth, Leyton sends the USS Lakota to stop it. Captain Benteen ultimately refuses to destroy the Defiant, Leyton resigns, and the emergency ends. The story weighs the cost of security against civil liberty.