The last two years haven't been easy for John Wells. Missions in Afghanistan, China, and America have taken a heavy toll on his body, his psyche, and even his soul. Now he is living quietly in Washington, trying to gather his strength and build his relationship with his lover Jennifer Exley. But his past is about to reach out for him, and for Exley.

Meanwhile, almost 6,000 miles away, terrorists are trying to steal a nuclear weapon, hoping to use it to provoke an all-out nuclear war between the United States and Russia. When the two plots come together, Wells will be faced with the most wrenching choice of his life -- and have the slimmest of chances to prevent Armageddon.