The Bounty (Fox and O'hare)

The Bounty (Fox and O'hare) by Evanovich, Janet. Library Binding edition. ISBN: 9781643588902.

Straight-as-an-arrow special agent Kate OHare and international con man Nick Fox have brought down some of the biggest criminals in the world. But now they face their most dangerous foe yet & a vast, shadowy international organization known only as the Brotherhood. Directly descended from the Vatican Bank priests who served Hitler in World War II, the Brotherhood is on a frantic search for a lost train loaded with $30 billion in Nazi gold, untouched for more than seventy-five years somewhere in the mountains of Eastern Europe.