A freak mishap in the wormhole propels Kira and Bashir into an alternate universe. Upon getting their bearings, the pair is astounded to learn that the Klingons, Cardassians, and Bajorans have formed an alliance, with the tyrannical Bajor calling the shots. Even more astonishing -- and terrifying, as far as DS9 is concerned -- is the fact that the alliance has enslaved all humans. Originally telecast on May 14, 1994, "Crossover" was written by Peter Allan Fields and Michael Piller. ~ Hal Erickson, All Movie Guide