O'Brien is arrested by Cardassians and given a show trial.
O'Brien sets off on a holiday with Keiko but is arrested by the Cardassians and taken to Cardassia Prime, where he is given a show trial: the verdict and sentence of death are fixed in advance, and his court-appointed advocate's job is to get him to confess. Odo uses a legal loophole to join his defence.
On the station, the crew learns that warheads have gone missing and that O'Brien is being framed as a Maquis helper. They find that his old crewmate Raymond Boone is a Cardassian agent surgically altered to look human, part of a Cardassian plan to discredit the Federation. Faced with the evidence, the Cardassians release O'Brien.