The Hansen kids are in a jam. Adam and his best friend Duffy have gotten their hands on some tickets for the Headless Horseman concert, and his sister Chelsea has a date with her dreamy boyfriend Peter. The only problem is they're both grounded. Chelsea and Adam will do whatever it takes to get their mom Lynette out of the house, even if it includes a chance meeting with a very mysterious man. Everything seems to go according to plan until their little brother Taylor realizes that this stranger might be a vampire.

Sydney Fox is a professor and globe-trotting "relic hunter" who looks for ancient artifacts to return to museums and/or the descendants of the original owner. She is aided by her linguistic assistant Nigel and occasionally by her somewhat air-headed secretary Claudia. She often ends up battling rival hunters seeking out artifacts for the money.