Twelve years after the events of Invasion!, Earth prepares to retaliate by mounting an expedition against the Martians. With great difficulty, our Space Force establishes bases on the two Martian moons, and also on the surface of the Red Planet. But a series of firefights demonstrate that the aliens hold the upper hand, and that communication between the species is the only thing that will keep our bases from being exterminated. Alex Smith once again must step forward, and offer himself as part-prisoner, guest, interpreter, guinea pig, negotiator, and--ultimately--the last, best hope of mankind. But finding any consistent and understandable method of communication with a truly alien race is almost impossible. Can the gulf be breached in time? War of Two Worlds, Book Two.