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.