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".
Angel (Buffy the Vampire Slayer episode)
The Master sends a trio of armoured warrior vampires after Buffy. They ambush her, but Angel arrives to help her. Angel is injured during the fight and Buffy invites him back to her house. When Angel takes his shirt off, Buffy notices a tattoo and asks him if he was stalking her, because she felt his presence at the Bronze. He shrugs it off. Buffy asks Angel why he fights vampires and he reveals that his family was killed by vampires.