Medieval Castle is a themed restaurant that Peter and the guys try to buy in "The Dating Game". Its Fiberglas facade disguising what was once a Midas muffler shop.
After the property is condemned, Al Harrington hosts the auction, noting that it has black mold, discarded, half-eaten turkey legs and an 'undulating' rat king that no one dare approach. Despite these flaws, the guys find themselves bidding against Mayor Adam West and his friends, Mort, Carl and Seamus. Mayor West opens the bidding at two bits, which Al recognizes as being 25 cents. Peter raises the bid to a mystery bag that may contain cash or socks, Mayor West counters with a mystery box with his original bid, noting it may contain a mystery bag. When a 'James Bond' villain bids 50 kroner, or $7.40, West bids $10,000, leaving Peter short when he only has $9000 in his mystery bag.
As West and his buddies celebrate by eating and planning a sleepover in the castle, Peter and the guys decide to take the "castle" the old-fashioned way by force, at first by using Joe's wheelchair as a makeshift jousting horse but are defeated when Mort accidentally opens the door at an opportune time. They then try to use flaming arrows, but their efforts set the whole place on fire.