Jordan Buchanan is thrilled that her brother and best friend are tying the knot. The wedding is a lavish affair–for the marriage of Dylan Buchanan and Kate MacKenna is no ordinary occasion. It represents the joining of two family dynasties. The ceremony and reception proceed without a hitch–until a crasher appears claiming to be a MacKenna guest. The disheveled and eccentric professor of medieval history warns that there’s “bad blood” between the couple’s clans, stemming from an ancient feud that originated in Scotland, and involving the Buchanan theft of a coveted MacKenna treasure.