Jack's been meaning to check out the Blood Shack for a while, and his recent encounter with Spike under the influence of the mistletoe-bots has only heightened his curiosity about the various vampires here. And when he discovers there's a chance to investigate them and make a show of himself on stage at the same time, well. Clearly, the time to visit the Blood Shack has come!
He shows up partway through the evening, wanders around a bit being charming and eventually gets up to sing Anything Goes, which of course suits him to a T in both style and content. He has a complete blast, laps up the applause, and then heads for the bar.
((OOC: Prose or brackets both welcome, I'm just starting with prose because it's easier (and bigger to read)! *g*))