Robert A. Heinlein

When Don Harvey's parents abruptly summon him from school on Earth to join them on Mars he has no idea he's about to be plunged into a deadly interplanetary intrigue. But from the moment he begins his journey he finds himself the subject of intense – and possibly deadly – scrutiny. Things only get worse when the ship Don is traveling on is unexpectedly diverted to Venus, where the colony has launched a revolution against Earth's control.