**** (4 stars out of 5)
There's been a coup among the Tzenkethi, on their home planet of Flimsy-Pretext. Somebody better rush out there in a gunship and rile them up or there might be another Federation-Tzenkethi War. (Like Sisko fought years ago: so terrible no one ever even mentioned them before.)
Someone on board is not what they seem!
We learn today that Defiant carries a crew of 47, only one of whom seems to be an engineer (O'Brien, of course) and most of whom can be confined to their bunk beds with no loss of ship's function. Take a lesson, Voyager (they can't run with less than 60 or 70)!
Also, we learn that nobody in this crew ever saw either the 390 or 360 year old movie 'The Thing'. Not even on Blu-ray. Or they'd have come up with their "defense" against shapeshifters a little faster:
Draw blood from a human- you get blood. Draw blood from a shapeshifter- not so much.
Of course, you really have to double up on blood guys in case of shifty-dickery. You need a buddy system for everything and nobody here can seem to manage it. (I can criticize through my Tostito-dusted lips knowing full well you'd be able to tell ME from the Shifter by the crap in my pants and the fact that I'd be dead before Act One.)
Again we hear the mantra from Chokey the Changeling while he's trying to spark an interstellar conflagration: "No changeling has ever harmed another." Sure, we attack Odo, but harm? Never.
But can you call it a victory if you defeat one drop from an ocean?
"The Adversary" is derivative but worthy. Great effects, good stunts, intense jeopardy, and especially strong paranoia. And Deep Space Nine gets even better NEXT season!