Ooo, look, Odo hassling Quark. Never seen that before. Quark's up to something with some twin Miradorns, apparently. They're trying to sell him an egg, but he's getting antsy because it may be stolen. Then another alien turns up wanting the egg thing, and, though Odo appears, one of the Miradorns is killed. The other Miradorn swears bloody vengeance. Odo expresses surprise that the other alien, Croden, had a Ferengi phaser and knew about the meeting. Croden also appears to know about other shapeshifters like Odo.
Odo hassles Quark some more, before confronting the remaining Miradorn (Ah-Kel) outside his office. Then Croden shows him a morphing necklace to prove the existence of other changelings in the Gamma Quadrant.
Sisko and Dax nip over to Croden's home planet and communicate with the natives. Who are mildly hostile and demand Croden be returned to them. Sisko says they'll bring him back in 52 hours. It takes that long to get there?
Bashir says the necklace is made of the same stuff Odo is, and Croden says he knows where there's a colony of changelings. However Sisko assigns Odo to take Croden back to Rakhar, so they sneak the prisoner off the station right past the Miradorns. Ah-Kel threatens to kill Quark and Rom unless they tell him where Croden is, so Quark hacks into the stations system and finds out. Ah-Kel sets off in pursuit.
Despite the fact that they said the Runabout could outrun the Miradorn ship, the Miradorn ship catches up and commences attack. Croden convinces Odo to hide in the Vortex, the area of space where he claims to have found a changeling colony. They land on an asteroid, where Croden admits he was lying about the changelings, and they find a stasis chamber containing Croden's daughter.
The Miradorns start shooting at the asteroid, and a rockfall knocks out Odo (I'm not going to ask how that's biologically possible). Croden carries him back to the runabout with his daughter, and they set about trying to evade the Miradorns. Odo lures them into a gas pocket and tricks them into blowing themselves up.
Some Vulcans suddenly turn up, and Odo spins them a story before turning Croden and his daughter over to be taken safely back to Vulcan. My, that was convenient. The end.