Angel (season 1)
At the end of the third season of "Buffy", the 242-year-old, re-ensouled vampire Angel left Sunnydale to give teenage Slayer Buffy Summers the chance to live a normal life. Angel is now living in the big city of Los Angeles. With Buffy gone Angel is now completely cut off from society, every day getting closer and closer to giving in to his vampiric hunger. It's not until he befriends the half demon and fellow Irishman Doyle, who is sent visions of people in trouble by The Powers That Be, and fellow Sunnydale resident Cordelia Chase, who grounds Angel's life in the humanity around him, that he truly begins to take charge of his life and seek atonement for his past sins. He sets up his own detective agency, Angel Investigations and begins to "help the helpless".
The Harvest (Buffy the Vampire Slayer)
The dark stranger appears again just as Buffy is about to enter the tunnel system in the crypt, and tells her his name is Angel. He gives her directions to The Master's lair, but pointedly refrains from wishing her luck until she is out of earshot. Xander catches up with Buffy in the tunnels, having decided to follow her anyway despite her earlier attempts at discouraging him. They find Jesse seemingly alive and unhurt, but he leads them to a dead-end in the tunnel system and then reveals that he has already been turned into a vampire. Buffy and Xander barely manage to escape.