"Sorry.  Without the backstory, the rest doesn't make sense.  Spent the next hundred-odd years travelling around with Drusilla, two little homicidal lovebirds.  She gets damn near torn apart by a crowd in Prague before I can save her, and she's weakened, beyond out normal ability to heal. So I bring her here to California.  To Sunnydale.  Without getting technical, there's a big spewing volcano of evil energy there.  And surprise surprise, there's my old Sire.  Only he calls himself Angel, and he's got a soul, and he's working for the good guys.  Hanging out with The Slayer, who's this supernatural chick with superpowers that fights all us nasty vampires. See, when he left, he never told us why, and neither did Darla, who knew.  But, nice little bonus...Sire's blood can heal almost anything that ails a vampire.  So I captured him, did a ritual that got interrupted.  Dru got healed anyway, but I was crippled.  Temporarily.  Church organ landed on me, snapped my spine."