When Vasily Petrov, a colonel in the Russian Foreign Intelligence Service posing as a diplomat with the Russian U.N. Mission, mysteriously disappears from a Russian oligarch's party in Southampton, it's up to Corey to track him down. What are the Russians up to and why? Is there a possible nuclear threat, a so-called radiant angel? Will Corey find Petrov and put a stop to whatever he has planned before it's too late?