Death in St. George's — M.A. Monnin

When Stefanie and Thomas meet in Bermuda for time alone away from the demands of the Artifact Retrieval Team that Thomas heads, their romantic rendezvous is waylaid after an archaeologist requests their help to recover an emerald bracelet that's been stolen from his site. 

Thomas is reluctant, but Stefanie can't resist the lure of buried Spanish treasure. Then one of the archaeologists is murdered, and they find themselves on the suspect list. Spanish gold isn't the only thing uncovered. Secrets can be deadly, and Stefanie and Thomas must find the killer before it's too late.