Continuing my season summaries:
Season 4 - Buffy and Willow are now freshmen at UC Sunnydale. Buffy's new boyfriend Riley is a member of the Initiative, a military operation that captures demons. Spike is captured by the Initiative but escapes, later discovering that a chip had been installed in his head that delivers excrutiating pain whenever he tries to inflict harm on human beings. When he discovers that he can still harm demons, however, he fights on Buffy's side (although towards the end of the season he plays both sides). A human-demon-robot hybrid named Adam, created within the Initiative as a secret project that few knew about, plans to create an army of hybrids like himself by setting the stage for a war between demons and the Initiative (which according to his plan would be aided by Buffy and Spike to ensure maximum casualties on both sides). Ultimately, Buffy is able to destroy Adam after Willow performs a spell to bestow upon her the combined skills that Giles, Willow and Xander possessed.