Sibling plumbers Mario (Lou Albano) and Luigi (Danny Wells) work in Brooklyn, New York. While unplugging a bathtub drain, the brothers are sucked in and warped to the strange Mushroom Kingdom. Soonafter, they rescue the beautiful Princess Toadstool (Jeannie Elias) and her wise-cracking assistant, Toad (John Stocker), from evil reptile King Koopa (Harvey Atkin) and his army. While trying to find a way home, Mario and Luigi continue to help the princess and thwart Koopa’s plots to overtake the kingdom.