The Return of Captain Conquer — Mel Gilden

In the house with two front doors, Watson Congruent's father sells souvenirs from the long-canceled TV show, The Adventures of Captain Conquer, and is also trying to build an actual "motivator," the device that powered the Captain's huge spaceship. And then one day Watson comes home from school to find both his house and father--vanished! With the help of some eccentric Captain Conquer fans, including the man with forty pounds of brains in his nose, Watson sets out to find his father--and not so incidentally, to save the world from an alien invasion. A great science fiction adventure for young adults--of all ages!