Chapter 218
Buffy explained everything to Winifred Burkle. Fred called Angel, Tara arrived soon after. By the time Angel arrived he'd already called Holtz, who arrived with him. Clearly Angel and Holtz didn't like working together, but were willing to do it. They began explaining everything to Buffy.
Holtz: More than two centuries ago, Angelus and Darla murdered my wife and children. I spent the next trying to kill them. A demon offerred me the chance to avenge my family's murder, he didn't tell me he would send me two centuries into the future. By this point Angelus and Darla had a baby Conner. Darla begged me to protect the child. As much as I hated them, the baby was an innocent I took him, raised him as my own, named him Steven. I met Justine, we raised him together. But I wanted Darla to suffer. There is a cave in Sunnydale, I trapped Darla inside. Decades before this there was a power struggle between rival vampires. One stood victorious, called himself the Master. He trapped his enemies within this cave. It has a spell, similar to what keeps vapires outside your home without an invitation. Once vampires are trapped within the cave they cannot leave. Darla would've rotted into a keleton. But if she is given blood she could theoretically be revived.
Buffy: Why didn't you just kill her?
Holtz: Because I wanted her to suffer.
Buffy: Like the Master wanted his enemies to suffer. You think Spike is trying to revive Darla?
Angel: No. We think Spike is working with Conner. Drusilla might be trapped inside as well. Maybe she came to rescue Darla and got trapped inside.
Tara: So they kidnapped Dawn to force me to break that spell?
Angel: Evidently. We'll help you rescue Dawn, but only if you promise to not hurt Conner. Not during battle, not after for revenge.
Buffy: Deal, provided Dawn isn't hurt either. If she is, all bets are off.