Firefax

"I would advise you, young man, to take care around anyone with the surname Firefax. I know not if the rumors be true that they be king killers, but they are, without any doubt, a dangerous family."
Legend tells of a city of gold on a phantom island. The wealth of that city could end the American Revolution. But the only person who knows the island's location is the world's deadliest assassin. And he's not giving up that secret without a fight . . .
The world's oldest family of high-profile assassins, the Firefaxes, have been killing off dignitaries-and being well-compensated to do so-for centuries. The family is thrown into turmoil by their patriarch's death and the return of their cunning, cruel prodigal, Murdoch. Murdoch is the only one left who knows where the Firefax wealth is, kept on a secret island. But Murdoch's former protégé, now turned nemesis, Istäni, who is the leader of a British intelligence network, and Murdoch's former colleagues from a Continental intelligence network are looking for that wealth. These spy networks are bent on tracking down the legendary treasure, whatever the cost, but may have met their match in the wily, dysfunctional family of killers.