By Ken Tucker
Updated February 06, 2009 at 05:34 PM EST

The best thing about last night’s Supernatural was the way it dramatized, in its distinctively paranormal, unsettling way, the rifts that have developed between brothers Sam (Jared Padalecki) and Dean (Jensen Ackles). The villain-of-the-week was a “siren,” an alluring figure that the Winchester boys were tracking down, responsible for making sane men crazy with what they think is just lust but which turns out to be blood-lust: at the siren’s bidding, the male victims kill a wife, a mother–any woman that the siren wants dead.

I’m sure you and I figured out that the hotsy doctor “Cara Roberts” (Maite Schwartz) was trouble from the moment she started coming on to Sam in her office. The truly unexpected twist was the way, after establishing via research unearthed by Bobby (Jim Beaver), that the siren was a woman, the brothers were ultimately seduced by one posing as a male FBI agent, because the siren sensed that only a man–specifically a surrogate-brother-type, not a woman–that could divide these brothers and prompt them to try to kill each other.

The siren-switch from female(s) to male made the episode a bit awkward; stripper-stripper-stripper-FBI-agent didn’t make for a very logical progession (or maybe you’ll explain for me–I can be dim about otherworldly things). But it did set up the evening’s emotional center: the fighting between Sam and Dean that the siren inspired brought to the surface all the roiling, unspoken emotions the guys have been feeling: about Sam’s ongoing involvement with Ruby; about Dean’s reluctance to reveal much about what went on during his time in hell.

The best stuff, for me, were the clever lines and the acting. Dean’s hearty, “Strippers, finally!” when he discovered the case led them to an exotic-dancer club; and (again, Dean’s line, after he figured out Sam had had sex with Dr. Cara) “[We’re in the] middle of Basic Instinct and you banged Sharon Stone?”

What’d you think? Which Supernatural moments did you like? Do you think the brothers’ bashing each other will have future consequences?