Through the Looking Glass

The mirror O'Brien kidnaps Sisko and takes him to the Mirror Universe, where Sisko's counterpart, leader of the Terran rebellion against the Klingon-Cardassian Alliance, has been killed. The rebels need Sisko for one mission. Jennifer Sisko, the counterpart of his late wife, is a scientist building a device for the Alliance that could expose the rebel base, and unless she is brought over, she will be killed. Posing as his double, Sisko goes to Terok Nor, the mirror station run by the Intendant Kira on Terran slave labour. He is captured, but gradually convinces Jennifer of the danger the Alliance poses. On his signal, O'Brien sabotages the ore processing equipment and the slaves break out. Trapped with the escapees, Sisko bluffs that he has set the station to self-destruct, forcing the Intendant to let them go. At the rebel base, Jennifer admits she knew he was not her husband, kisses him goodbye, and Sisko returns home.