In thirteenth century England, Doug and Tony become involved with the Earl of Huntington otherwise known as the legendary Robin Hood and their efforts to get King John to sign the Magna Carta.

Doug and Tony are transported to a spacecraft with two weird aliens that intend to invade Earth to steal proteins for their dying planet. They land on Mullins, Arizona, in 1885, and the aliens use a device called "Projector" to subdue the earthlings. The time travelers decide to resist the invasion to save Earth from the eminent destruction, but the powerful aliens seem to be unbeatable.