Buffy and bed buddy Spike are knocking boots so hard, it busts up the furniture in his chamber. The bleached bloodsucker likes bein' a playa with the Slaya, and Buffy is getting worried about his power over her. In the Evil Trio's new lair, technogeek Warren shows Andrew and Jonathan his new invention: a small globe he calls the Cerebral Dampener. Chanting a spell, the globe erupts into a glowing pillar of energy. Warren brags: the Dampener will turn any woman into an eager sex slave. Over at Doublemeat Palace, Tara finds Buffy working the counter. The Slayer confesses her growing fear of Spike's power over her. That same night, the Evil Trio is huddled inside their video van, cruising chicks by secretly watching them on monitors. As Warren scopes women with a tiny camera in his tie tack, he spots his ex, Katrina. He flashes the Dampener on her, and bam! she's his love zombie. When an exhausted Buffy comes home from work, she finds Dawn mad at her for not being around more. Xander says some frosty fun at the Bronze is needed by all, and Buffy agrees. Back at the nerd lair, love-slave Katrina serves champagne to the trio. Warren loves his ex obeying his every command. But when the Dampener whammy abruptly wears off, an angry Katrina tosses the evil-doing dork into the next room. Katrina is so furious, she fights the trio single-handed, until Warren cracks her head with a bottle of bubbly. Falling hard onto cement stairs, Katrina is kaput. The trio argues about how to get rid of the body, and how to stop Buffy from finding out. Warren gets an idea: maybe he can kill two problems with one stone. Over at the Bronze Willow watches lovebirds Xander and Anya spaz-dance, as Buffy finds Spike ready to do some "dancing" himself. While he and Buffy get it on in the balcony, Spike whispers temptations to join him on the dark side. At the Magic Box, Tara and Willow have to fight temptations to perform their own kind of magic. Needing a distraction, the Slayer goes out to slay. In the cemetery she finds a Rwasundi demon attacking what appears to be a very-much-alive Katrina. Now things get weird. Suddenly, Buffy is hyper-thrust from one location to another – and back – hearing voices, fighting demons, confronting Spike, even punching Katrina. In the confusion a shocked Buffy discovers Katrina's very real and very dead body. But lurking in the shadows is another "Katrina." From inside the Evil Trio's video van, we now see the whole thing was set up and monitored by the "other Katrina," who is glam-revealed to be Warren. He's proud of his magic: he's got Buffy believing she killed Katrina. Spike comforts the stunned Slayer, but suddenly things go all David Lynch again. Buffy finds herself making rough love -- not to Spike, but to "Katrina." Once again, she's thrust from place to place, lashing out at a shape-shifting attacker. It's a nightmare which Buffy only partly wakes up from. She tells Dawn she's got to turn herself in for murder. Spike stops Buffy from going to the cops. He tells her he got rid of the body because he loves Buffy. She clocks him. When Spike says he'll even take the rap for her, Buffy bloodies the bloodsucker up real bad. She reminds Spike he has no soul. She can never be his girl. As she goes to the police to confess, a memory-flashback of Warren and Katrina arguing makes her realize: the geek must've killed her. She bails on confessing. Back home, Xander tells Buffy the cops found Katrina's body. The coroner rules it a suicide. Anya explains Buffy's hallucinations with the Rwasundi demons. The Slayer now knows this is Warren's handiwork, and the evil geek is getting away with murder. But Buffy has other problems. In tears she confesses to Tara that Spike has been her secret lover. Tara promises the guilt-wracked Slayer that she'll never, ever tell.