Philip Crane suddenly learns that his father was a native of Mars, one of the warriors of the Red Planet's invasion force who accidentally landed and became stranded on Earth. And Philip's half-brother is the current ruler of Mars! Teleporting to Mars with the help of a found matter transmitter, Philip Crane finds himself drawn into Martian political intrigue, the struggle for the throne of the ruler of Mars, and, due to the fact that he is a copy of his brother, replaces him on the throne... The Earth is attacked by turtle people living under a dome on the reverse side of the moon. They come from Earth, but they once captured this satellite, exterminating all the intellectual worms there, and now they plan to triumphantly return to their historical homeland...