Astounding consequences occur when the U.S.S. Voyager, while attempting to evade a pursuing Vidiian vessel, enters a plasma cloud. Before they can clear it, the engines stall, anti-matter supplies drain and a proton burst, originating from within the ship, cause heavy casualties and breaches the structural integrity of the hull. When Ensign Kim and Kes disappear into a void in space, Captain Janeway discovers that a duplicate Voyager with an identical crew exist in a parallel universe.
