The Initiative's more sinister secret purpose is revealed when its composite demonic cyborg, Adam, kills Walsh, then escapes and rampages through the town. After getting Spike to temporarily work for him, Adam plots to create others like him to overthrow humanity, although Adam sees Riley as his "brother". Buffy and her allies unite to defeat Adam and destroy the Initiative. The demons and other supernatural creatures fight back against their former captors, while the Scoobies temporarily transfer all their skills into Buffy to fight the physically superior Adam. Magically enhanced, she kills Adam by ripping out his uranium core. The Initiative is defeated and the Scoobies recover. The government recognizes that Prof. Maggie Walsh's plan is a failure, and orders her project to be terminated. The Scoobies later encounter the spirit of The First Slayer, who gives Buffy a cryptic message. Cast and characters Main cast Sarah Michelle Gellar as Buffy Summers Nicholas Brendon as Xander Harris Alyson Hannigan as Willow Rosenberg Seth Green as Daniel "Oz" Osbourne Marc Blucas as Riley Finn James Marsters as Spike Anthony Stewart Head as Rupert Giles Recurring cast Guest cast Crew Series creator Joss Whedon served as executive producer and showrunner, and wrote and directed four episodes including the season premiere and finale. Marti Noxon was promoted to supervising producer and wrote or co-wrote five episodes. Jane Espenson was promoted to co-producer and wrote or co-wrote five episodes. David Fury, who as a freelancer had written or co-written three episodes in seasons 2 and 3, was hired as producer and wrote or co-wrote four episodes. Douglas Petrie was promoted to executive story editor and wrote three episodes. The only new addition was Tracey Forbes, who served as a staff writer and wrote three episodes. James A. Contner (also co-producer) directed the highest number of episodes in the fourth season, directing six episodes. Joss Whedon and David Grossman each directed four. Episodes Crossovers with Angel Beginning with this season, Buffy the Vampire Slayer and its spin-off Angel both aired on The WB Television Network. Both shows aired on Tuesdays, Buffy at 8:00 PM ET, and Angel at 9:00 PM ET. The fourth season of Buffy aired along with the first season of Angel. Both shows featured crossover episodes, in which characters of one series appeared in the other. Angel (David Boreanaz), Cordelia Chase (Charisma Carpenter) and Wesley Wyndam-Pryce (Alexis Denisof), who had been introduced