Garak, Odo, Dax and Sisko are on their way back from Bajor in a runabout. Some conference didn't go well, in Garak's opinion. The others don't think Odo should be quite so humble about his actions during the occupation. The station picks up their runabout, but detects only faint lifesigns on board. Worf and Bashir beam on board to find everyone unconscious.
Sisko finds himself on the Promenade, but the Cardassians are in control of the station. The four are roused by a Bajoran who tells them to pick themselves up.
Bashir examines the four unconscious people, and Worf says the runabout passed through a plasma storm. The computer doesn't have anything on file.
Sisko's group realise that they're somehow on DS9 during the occupation, and that everyone sees them as Bajorans. Dax theorises that their minds have been sent back in time and implanted in new bodies. Odo is alarmed and says they need to get out of there. They spot Gul Dukat and move to another part of the station. Odo is briefly accosted by a Bajoran who turns out to be Thrax, Odo's predecessor. The Cardassians arrest Dax - Garak tries unsuccessfully to bribe them and gets punched in the fact for his troubles.
In the real world, Worf notices Garak has a bleeding nose. Bashir thinks it's a psychosomatic response.
Sisko's annoyed that Dax has been taken to places unknown. Garak's nicked a Cardassian device which he uses to identify who the people they've possessed are, but after hearing Sisko and Garak's identity, Odo already knows who he is. The trio are picked up as workers by Quark. Odo wonders if it would damage the timeline if he damaged Quark, and this gives Sisko the idea to try an experiment. Meanwhile, Dax is taken to Gul Dukat and assumes the name Leeta. He wants her to be his friend.
In the bar, Odo says that the three people they're occupying were Bajorans who were falsely accused of trying to assassinate Gul Dukat and executed. They realise that they're going to need to get the hell off the station.
Thrax chats with Quark about his meeting with a freighter captain, but Quark denies dealing with the captain. Garak remembers that the captain was actually a Romulan spy and checks the date - it's only seven years ago, and Odo should be head of security. Sisko wants to contact the Bajoran resistance. After turning a vase upside down, they spot Dax with Gul Dukat. A resistance member approaches them, but during the discussion, there's an explosion, and Sisko, Odo and Garak are arrested when they run to Dax's aid. Odo unsuccessfully argues with Thrax.
Dukat tells Dax that this is the fourth assassination attempt he's survived. Dax renders him unconscious.
Sisko asks Odo about Thrax, believing he knows something. Then Dax burns through the back of their cell and their head for Dukat's personal shuttle. On the way, they're ambushed by Cardassians including Thrax, who turns out to be a Changeling. They reach the shuttle, but find themselves back in the security cell.
The others realise Odo does know something he's not telling them. Odo talks to Thrax alone, trying to persuade him that they're innocent again. Then he tries to persuade Thrax but they're from the future, but Thrax already knows and calls him by name. At the execution, Odo knocks the gun from the executioner's hand, announcing that Thrax shouldn't be there, he should be. And then he admits he was the one who sentenced the innocent Bajorans to death, not Thrax, and only found out three days later when there was another bombing.
The four wake up in the infirmary and Bashir tells Odo that they were in some version of the Great Link. Kira pays Odo a visit to ask if any other innocent people died while he was head of security, but he doesn't know. Teh end.