An eccentric American inventor, Cyrus Grant, recruits a British physician and explorer, Archibald Riley, and a fellow Englander, Detective Henrietta Honey, to accompany him on an expedition to the moon. Meeting in Tombstone, Arizona, the American assuages the concerns of the Brits, and without wasting any time, they take to the sky using Cyrus’ newfangled propeller, soon plunging into the ether. Everything goes fine as they reach the surface of the moon, but in a split second, everything changes.