Season 7 Episode 8 - Sleeper
Buffy anxiously awakens Xander in the middle of the night following her discovery that Spike sired Holden. Spike has been staying with Xander, but the Vamp is out for the evening. In fact, Spike is burying his latest kill in a shallow grave as he hums a jaunty tune.
In London, a man bursts into a home to find the body of a dead girl on the floor. Though he makes a valiant effort to defend himself, he takes a knife in the back from a now-familiar black robed figure.
Xander and Buffy argue over Spike's current status: killer (Xander's opinion) versus non-killer (Buffy's). Spike gets home, and when Buffy subtly questions him about his late-night doings, she's surprised he doesn't flinch at a mention of Holden. Spike heads off to bed, and Buffy decides someone needs to keep an eye on him. Anya's enlisted, and though she's nervous, she agrees to stay at Xander's and keep watch.
Buffy gets home to find Willow putting Dawn to bed. The girl was freaked, and Buffy is devastated to learn she saw the ghost (maybe) of their mother. Buffy doesn't know whom to trust about recent events, and determines she needs proof of Spike's misdeeds either way.
Outside Spike's room, Anya is nervous. Twitchy. She's convinced that if Spike is killing, he's keeping trophies of his victims in his room (like drinking their blood isn't enough). She enters his lair carefully and searches, but he awakens and grabs her. She fumbles a bit till she comes up with an explanation: sex. She wants sex, with Spike! The Vamp is flattered (sort of) but turns her down, and Anya escapes unscathed. When Spike departs for the night, Anya calls Buffy.
The Slayer trails Spike through a crowded town square and spots him chatting up a young woman. She loses the two of them in the crowd, and Spike pulls his willing target into a dark alley. He's set to dig in when he sees Buffy over his shoulder, but Spike's getting duped by the Big Bad too. The vision of Buffy seductively encourages him to make the kill, and he eagerly complies.
The real Buffy catches up with Spike later that night, demanding to know the truth. Spike denies he's been killing, and accuses his ex of being jealous. He's very convincing, and is actually shocked when Buffy throws the subject of Holden in his face. Confused, Spike again denies it, but his memory is a little fuzzy.
The next night, Xander tries to keep Spike at home, but gets knocked out for his trouble. At the Bronze, Spike asks around about the woman he'd been there with the other night. A woman approaches and flirts with him; she turns Vamp on him and offers to pick off the crowd. He refuses and she attacks, insisting that since he sired her, he ought to give her a hand. Horrified, he stakes her.
Outside the Bronze, Buffy questions the bouncer, who recalls a Billy Idol wannabe leaving with a different girl every night. Her phone rings; it's Spike, wanting to see her. He's starting to remember doing very bad things.
They meet in the basement of a creepy abandoned house, and Buffy is edgy (and armed). Spike points to the dirt floor of the basement: he's been burying his kills there. The morphing First demon lurks in the background in the guise of Spike, humming. Real Spike hears the tune and flips out, attacking Buffy as the dead rise from the ground. The new Vamps grab Buffy and offer her to Spike, and he takes a lick of blood from a cut on her arm.
In a flash, all Spike’s recent crimes come flooding back into his memory, and he jerks away in horror. With that, Buffy makes quick work of the new Vampires. The First whispers to Spike that since he failed, Buffy will kill him. Spike's ready to die to escape the demon haunting him, but instead Buffy sits with him. The Vamp breaks down in tears, begging her for help. Reluctantly she agrees, as the First looks on in disgust. Buff takes Spike home, wanting to keep him close so the gang can learn everything they can about the Big Bad.
In London, Giles bursts into the home of the dead girl, and finds the other man stabbed. The man's eyes fly open. "It's started," he gurgles, just as a ghoulish robed figure swings an axe at Giles' head. Hello, cliffhanger.