10 Most Shocking Betrayals In Star Trek
4. Gul Dukat - By Inferno's Light
Ok, no one ever thought that Gul Dukat was a good man. Yet, his switching of sides in Deep Space Nine's fifth season did still manage to come as a bit of a shock.
Captain of a captured Bird of Prey, Dukat was a shell of his former self by the time he negotiates for Cardassia to join the Dominion. All that this man has ever lusted for was power and so the fact that he then propels Cardassia into the most powerful union it could find itself in should come as no surprise.
However, this was after five years of character development. Dukat had often managed to establish himself as a grudging ally to Sisko along the way. When the Klingons invaded Cardassian space, he was rescued by Starfleet in a daring mission that cost many Federation lives. His daughter was cared for on the station by Major Kira, a woman he had been mortal enemies with. The stage had well and truly been laid for his eventual joining forces with Sisko against the Dominion.
Instead, he becomes the direct cause of their advancement into the Alpha Quadrant. His cold message to Kira before joining the Dominion fleet sums the situation up succinctly. He bids her well, remarking that the two of them on the same side never truly felt right. Before she can order his ship destroyed, he warps away and the road to all out war begins.