The owner of a Miami salvage company steals a fortune in Russian diamonds and then disappears. His beautiful con artist sister is coerced into becoming an undercover government operative in order to recover the diamonds and rescue her brother.

When the second yacht in a week is hijacked off the Florida coast, Roberts sends Kate equipped with a sixty-foot Italian Baia yacht, to turn the tables on the trio of thieves.

Kate makes a bet with her stakeout partner as to who will be the first to crack a case involving a senator suspected of being on the take.

A stolen Cellini chalice is the elusive treasure for which Roberts sends Kate, who must pose as a diver, renew an old friendship and out-think a devious pair of thieves.

Missing: $3 million in gold bullion... and the man who may have stolen it. Meanwhile, Kate is asked to ""baby-sit"" his girlfriend.

Kate goes undercover, managing a Haitian bistro, to investigate liquor smuggling and to find and protect the boy who witnessed the former manager's execution.