While en route to the station, Major Kira and Dr Bashir intercept a damaged Kobliad freighter. Onboard they find a security guard, Ty Kajada, and her dying prisoner, Rao Vantika. Despite Vantika's death, on arrival at Deep Space Nine Kajada insists her prisoner may still be alive. Has Vantika somehow faked his own death, and transferred his consciousness into someone else's body?
Here we go again: great concept, dreadful execution. This was originally a really cool concept for an episode of Star Trek, with a police officer trying to hunt down a vanished criminal only to learn that the criminal is actually hiding inside their own mind. It brings to mind all manner of Philip K. Dick novels and stories, and could have been a wonderfully twisted story rich with paranoia. The problem of course is that it would have been based around the guest star, with the regular cast relegated to supporting roles. That makes a certain amount of sense, and there's another good episode to be made here where we don't know which of the station command crew has been secretly possessed.
Except we do know, because for reasons known only to its creators "The Passenger" flat-out tells us within two minutes of the episode starting.