Jake can hardly believe his eyes when his father introduces him to a woman who appears and acts exactly like his late mother, Jennifer. Sisko reveals that this is Jennifer -- at least her double from a mirror universe which Sisko once visited, where she was married to his now-dead counterpart. Sisko leaves the two of them alone for awhile. When he returns, Jennifer and Jake are nowhere to be found. All that remains is a small device. Sisko uses it to transport to the mirror universe, appearing on the alternate Deep Space Nine. He is then taken prisoner and told that the rebels of this universe need his help in their fight against the tyrannical Alliance forces, led by Worf.