Author(s): Robert A. Heinlein
Jim Marlow and his strange-looking Martian friend Willis were allowed to travel only so far. But one day Willis unwittingly tuned into a treacherous plot that threatened all the colonists on Mars, and it set Jim off on a terrfying adventure that could save--or destroy--them all From the Paperback edition.
1990. Reprint. A near fine, tight copy.