The Lost Key by Catherine Coulter and J. T. Ellison
The second Brit in the FBI novel featuring Nicholas Drummond.
After working with Special Agents Lacey Sherlock and Dillon Savich, Nicholas Drummond has joined the FBI. Now, he and partner Mike Caine are in an eleventh-hour race to stop a madman from finding a cache of lost World War I gold—and a weapon unlike anything the world has ever seen . . .