A gang of kids helps a sea captain search for a pirate’s treasure that’s rumored to be hidden somewhere in the old dilapidated inn the sea captain just inherited from his dead brother. Along the way, they unravel a series of clues which lead to a variety of hidden passages and trap doors. But they are not alone in their quest for Jean Lafitte’s pirate goodies!

An American foreign exchange student in Ireland, Rich Evans (Kurt Russell), gets caught up in espionage when a dying man gives him a message to pass to his older brother, who is an American intelligence agent unbeknownst to Rich. Rich and his friend are then kidnapped by an Eastern Bloc agent pretending to be from the American Embassy in the hopes that they will lead him to a scientist who is attempting to defect to the West. Originally aired in 3 parts on 'Walt Disney's Wonderful World of Color' TV series, then re-edited into a theatrical feature in Europe under the title, 'The Secret of Boyne Castle.'

《魔力神童》是迪士尼70年代超能力神童系列的最後一部電影，故事主角依然是那位奇遇不斷的大學生 Dexter Riley 這次又有狀況了，他和他的夥伴們在實驗室意外之下將一種維他命麥片和化學藥劑混合，居然創造出神奇的功效，一開始他們把麥片給隔壁養的乳牛吃了，居然乳牛活力不斷，牛奶供應絡繹不絕。後來沒想到 Dexter Riley 居然自己也誤食了，而因此成為一位大力士，舉起數十磅的物體都是輕而易舉。學校的 Higgins 院長知道這消息，他以為是這種廠牌的麥片都有這神奇功效，為了讓校隊參加舉重比賽獲勝，他便和親戚所經營的這家麥片廠商達成交易，但是院長卻不知一切都是 Dexter Riley 所加的化學藥劑在發揮功效。另一方面，麥片廠商的另一家競爭者心存懷疑，便派出手下來暗中搞破壞，並刺探事情的真相。