Recap / Star Trek: Deep Space Nine S04E12 "Paradise Lost"
As Starfleet enforces sweeping security reforms on Earth, Sisko investigates the threat of Changelings and the Dominion. But mounting evidence indicates the entire situation could be an inside job.
Bavarian Fire Drill: Sisko hauls in a Red Squad cadet for a chewing out, making the cadet believe Sisko's in league with Leyton. Sisko then demands the cadet walk him through the plan to sabotage the planetary power grid to explain their "damn sloppy work".
False Flag Operation: Leyton has Red Squad disable Earth's entire power grid, then blames it on Changeling infiltrators.
Frame-Up: Leyton fakes a blood screening to make Sisko look like a Changeling infiltrator, thus getting him out of the way.
Graceful Loser: Once it's clear Leyton cannot win, he quietly takes off his rank insignia in resignation.
Insignia Rip-Off Ritual: Sisko pulls off Leyton's combadge when demanding his resignation. Leyton then takes off his admiral bars when admitting defeat.
Revealing Cover-Up: Sisko and Odo notice a transporter log indicating that Red Squad was beamed back to the San Francisco just after the blackout, then mobilized just three hours later. When the Academy commandant asks Sisko to erase that log entry, because it might cause problems, it's their first hint that something bigger is at work.
Sheathe Your Sword: The Defiant has the Lakota on the ropes, but doesn't deliver the killing blow. This convinces Benteen to disobey her orders and turn on Leyton.
That's an Order!: When Nog is reluctant to provide Sisko with the names of Red Squad, Sisko points out that it wasn't a request. He wants a name, he wants it now, and that is an order!
Villainous Breakdown: Leyton seems to start one as his plans go south, but ultimately reins it in and resigns quietly.
What Happened to the Mouse?: We never find out what happened to the actual changeling infiltrators on Earth who bombed the Antwerp conference.