A Soviet agent has entered the United States—carrying a terrifying weapon—in this Cold War thriller by the #1 New York Times–bestselling author . . .

Agent Andy Clayton has been inactive for eighteen months, kept under tight surveillance at his home in Washington D.C. Now he is needed—Leonid Borikowski, code name Dragonfly, has been seen entering the United States, and Clayton is the only man who may be able to find and stop him.

For Clayton, it's more than a routine assignment. He knows Dragonfly, has faced him before, and he wants him. His interest is as personal as it is professional: He wants revenge on the foreign agent who killed his twin brother. But there is much that Clayton doesn't know. He doesn't know that Borikowski is carrying perhaps the most important, and dangerous, biological discovery the world has ever known. He doesn't know that the microbe is in a suitcase armed with a device that will explode if Borikowski is harmed. And he doesn't know about the Soviet intelligence project code-named Bookends—a project that will not be complete until Andy meets the same fate as his brother. The chase will take him across the United States and Canada, putting himself, the woman he loves, and thousands of innocent people in jeopardy…