The Shadows of Rhodes, Book 5: The Red-Eyed Cat

Smugglers and art thieves have been threatening Helena to give up the photo, as it has something to do with ancient hidden treasures. When a major breakthrough is found in London which brings all the other clues together, they finally realize the solution has been staring them in the face all along. Relentless in the pursuit of the photo, which is hiding incriminating information and a poem within its backing, the crime boss is ready to take the found clues, at any cost. The end of the rainbow is in sight, and so is VanderBur and his minions.