A hunter arrives on the station chasing a prey who is not what he seems.
A damaged ship from the Gamma Quadrant brings Tosk, an alien who appears to be fleeing danger, and O'Brien befriends him while helping repair his vessel. Tosk is jailed after trying to raid a weapons locker, and armed Hunters then beam aboard, revealing that Tosk is their prey and was bred to be hunted.
Sisko feels obliged not to interfere with the alien custom and agrees to hand Tosk over, while the Hunters agree to keep future hunts away from the wormhole. O'Brien, knowing Tosk would rather die than be captured, tricks Odo, disables the Hunter at an airlock and helps Tosk escape, with Sisko quietly letting it happen.