Ignoring the warnings of the Prophets, Starfleet takes the offensive in the Dominion war, and Sisko is chosen to lead the invasion of Cardassia. While the first target is the supposedly vulnerable Chin'toka System, the crew is unaware that the Cardassian/Dominion Alliance has secretly deployed hundreds of orbital weapon platforms to protect the system, and that Gul Dukat has returned claiming he has the key to victory. Returning to the station, the Defiant crew realize that they are too late to save Jadzia Dax and the sacred orb which has been destroyed. Believing that he has failed in his role as the Emissary and Starfleet Captain, Sisko decides to return home to Earth.