During the American Revolutionary War (1775-1783), the patriot Jonathan Wellington "Mudsy" Muddlemore and his pet cat Boo hid in a grandfather clock to escape arrest by the Redcoars. Unfortunately for them, they could not escape the clock and suffocated to death while trapped inside. In the 20th century, teenage girl April Stewart and her two prospective boyfriends Skip Gilroy and Augie Anderson are traveling the country in their dune buggy. Searching for a place to spend the night, they enter the long-abandoned house of Muddlemore. Around midnight, they notice the grandfather clock displaying the wrong hour and try to set it right. These releases the ghosts of Muddlemore and Boo, who befriend the teenagers. Afterwards, the teenagers act as amateur detectives, investigating mysteries which they encounter in their travels. Muddlemore lends a helping hand in their investigations.