Xander uses a fake ID to get a job as a bartender on campus. Buffy gets drunk on Black Forest beer with 4 fellow college boys. Meanwhile, Oz and Willow at the Bronze and Oz feels a strong connection with the lead singer of the band playing which startles Willow.
Willow is still upset over the previous night and Buffy is acting strangely the next morning. Buffy keeps drinking more and more of the Black Forest beer. Xander discovers that the bar owner is making the beer to exact revenge from his college days. The beer turns you into a violent Neanderthal. Xander had sent Buffy home before this discovery but the 4 college boys she had been drinking with, turn and the boys escape to the streets of Sunnydale. Xander goes to Giles for help and when they reach Buffy's dorm, they see Buffy drawing cave drawings on her wall having turned over. She speaks in short sentences such as "Parker bad.". Buffy runs off as she gets more craving for beer.
Meanwhile, Willow has confronted Parker over what he did to Buffy. He tries to charm her, but she doesn't buy it. The 4 Neanderthal students come in and knock both Willow and Parker unconscious and start a fire which quickly grows out of control. Xander catches up to Buffy and they both stop the fire. Though Buffy is afraid of the flames, she manages to save Willow and Parker.
Parker thanks Buffy for saving his life and she boinks him on the head with a club.
This episode originally aired on November 2, 1999.