Sifting through reams of seemingly unrelated intelligence, CIA analyst Katharine Rule discovers a chilling pattern: a rash of Russian submarine sightings in the Baltic Sea...a crafty Soviet spy-master in command...a carefully planned invasion about to be launched.

Her suspicions, however, are dismissed by those higher up. They say her theory is too crazy to be true. But to Katharine, it's just crazy enough to succeed, unless she can stop it. If she's right, an attack sub has already penetrated friendly waters. Worse yet, the enemy has penetrated deep into her own life, so deep she can touch him. And in this game, one wrong touch can mean a new world war.