The campaign was set in Monte Cook's Ptolus. The players had gone to capture one of the big bad guys of the campaign, Navanna Vladaam. I don't even remember why they wanted to capture her now. I only remember that the plan was for her to be captured, give up some info, and then escape and continue being a bad guy. Of course, they didn't capture her, they killed her. From my memory, it went something like this:
Me: "Well she's dead. Now what?"
Cleric: "I can raise her."
Me: "That will take a while, are you sure you want to do it right here? You are in her house and just had a big loud fight."
Cleric: "I know! I'll Gentle Repose her! We can raise her later." (Gentle Repose allows you to preserve a dead body for a period of time so it can be raised later. )
Me: " Okay you are back in your hideout, you want to raise her now?"
Ranger: "Nah, then we'd have to keep her prisoner and she could escape. Let's just keep her Gentle Reposed until it runs out then we'll raise her. Stick her in the closet."
And so, my big bad evil guy ended up being in the closet of their hideout for a while. They did eventually raise her and get the info they wanted. By that point, I had already transferred everything she was supposed to do to a new BBEG, as you do.