The Killer In Me
To help the Potentials understand their powers, Giles is taking them on a little camping trip for some meditation and visionquesting. After they leave, Buffy greets a chained-up (by choice) Spike downstairs, but is horrified when the Vamp screams out in pain, blood dripping from his nose.
While Buffy worries over the possibility of Spike's chip malfunctioning, Willow brews some tea for Kennedy, who's upstairs nursing a cold. Upon delivering the tea, Will finds Kennedy looking "surprisingly robust and casually dressy" for someone who is ill. Kennedy faked sickness to pursue her own mission: to take Willow on a date. At the Bronze, Kennedy seriously flirts with an off-kilter Will. The Slayerette turns on the charm full throttle as they discuss their histories, and soon Willow is quietly receptive to the attention.
Meanwhile, Spike's in almost constant pain, and he's pretty sure it's related to the chip. Buffy tries to contact Riley to see if the former Initiative operative can help, but when she's only able to reach a flower shop, she quips, "It's either a wrong number or a giant government conspiracy."
Back in Willow's room after their date, Kennedy leans in and kisses Willow. Kennedy's got a dreamy look on her face until she opens her eyes to see the face of Warren staring back at her. Kennedy freaks, and Willow is horror-stricken to see the image of her dead nemesis in the mirror instead of her own face. She races downstairs and is confronted by the gang, including Buffy, who takes a swing at her. Him. Whatever. It's only once Buffy makes physical contact that they realize Willow/Warren isn't the First (since the First can only take non-corporeal form.) Willow takes off to fix the enchantment herself, convinced it's her own guilt that has brought it on. She has no luck, but Kennedy shows up to help, and Willow grudgingly allows her to come along.
At the Summers house, the Scoobies get a call from England that arouses their suspicions. They hear about how Giles had been on the wrong end of an axe swing, but no one knows how he could have escaped. Worried that they've left the Slayerettes in the hands of the First, everyone (including Andrew) sets out to find them.
Willow and Kennedy show up at a UC Sunnydale coven meeting seeking help, and Will is shocked to find Amy there. The former rat has been attending meetings, trying to sort out her own problems, and is sympathetic to Willow's plight. She offers to help by performing a chant, but when she does, Willow hauls off and slaps her. Warren has surfaced briefly and is trying to take over Willow's personality. Willow takes off, throwing a spell to keep Kennedy from following her.
Willow--uh--Warren ends up at a gun shop. S/he makes a purchase, which can only mean one thing: trouble.
Buffy and Spike locate the old Initiative’s underground caverns, hoping to find a solution to the chip problem. When they break in, they find dozens of demon corpses left to rot when the military sealed the place. Unfortunately, the demons aren’t all dead, and one of them attacks and drags Spike away. Buffy chases him, and ends up killing the demon just as the lights come up. It's the military! Riley apparently got the message and instructed them to do whatever Buffy needed. "I knew it," she cries, "a giant government conspiracy!" They offer assistance to Spike about the chip, which they can either repair or remove. It's up to Buffy.
After a long car trip into the wilderness, the gang attacks Giles, feeling him up in a rather suggestive manner. Fortunately, he's as corporeal as they come, and the girls are all safe. Crisis averted.
However, another crisis arises for Kennedy, who realizes that Amy's not nearly as sympathetic towards Willow as she pretended. Evidently, Amy's at fault for the Willow/Warren transformation. Envious of her enormous power, Amy placed a hex on Willow that allowed her to choose her own punishment. Out of guilt, Willow is now losing her identity. Kennedy is not about to let that happen, but Amy snaps her fingers and sends her to the Summers backyard just as Willow comes roaring in, gun in hand. It's a reenactment of the day Tara was killed, only this time, Willow's the would-be shooter. She raves at Kennedy, who's confused by Willow's ramblings. Turns out Willow isn't feeling guilty for killing Warren, but for forgetting, even for a moment, Tara. It's killing her to let go of her dead lover, but Kennedy realizes the spell can be broken, just like in fairytales, with a kiss. When she pulls away, Willow is herself again, and arms wrapped around each other, they go quietly into the house.
Summary from Buffy.com