At key points throughout North America, an invasion force is taking over communications, government, industry-and people's bodies. And the nation is helpless to stop it because the invaders multiply far faster than they can be destroyed, controlling the mind of every unsuspecting person they encounter....

Enter Sam Cavanaugh, a can-do intelligence officer for the United States' most secret service. Cavanaugh is the only man who can stop the invaders. But to do that he'll have to be invaded himself!

This book is not connected to the same tiled movie starring Val Kilmer.
Willis was a bouncer, a Martian roundhead who looked at all the world like a hairy medicine ball and who could-and often did-function as a complex recorder of what went on around him.

To Jim Marlowe, he was simply a friend; and wherever Jim and his pal Frank went, Willis went too. But they didn't go far, since their forays were limited by strict rules.