Hop Harrigan (William Bakewell) and his pal "Tank" Tinker (Sumner Getchell) operate a small airport and flying service, and are hired by J. Westly Arnold (Emmett Vogan) to fly an eccentric inventor, Dr. Tabor (John Merton), to his secret laboratory where he has a revolutionary new power unit. However, a mysterious character known as the Chief Pilot is interested in the invention and uses a destroying ray to cripple Hop's airplane and kidnap Tabor. Hop and "Tank", aided by Gail Nolan (Jennifer Holt and her younger brother, Jackie (Robert 'Buzz' Henry), finally overcome the villains - and, then, Tabor goes mad and decides to blow up the world. There is still work to be done.