The Papal Secret by Stanley Miller

When Pope John Pietro 1 receives news from a strange visitor he learns a secret that shocks him to the core. Not wanting to cause turmoil within the Holy See, the Pope and his trusted friend Cardinal Pollini make a pact to keep the revelation secret until the full ramifications of the predicament can be analyzed. Meanwhile a prominent banker is found murdered on a pleasure yacht and suspicion falls on the remaining five passengers and crew of three. Michael Frost, the owner and captain of the yacht, tries to clear his name as a suspect. Strange circumstances surround the murder. An emblem on one of the murdered man's documents implicates Vatican involvement. Michael must do everything he can to expose the Vatican’s murderous scheme after learning that the Pope is due to sail on his boat. Alone against the Pope’s powerful enemies, Michael will confront deadly locales and dangerous evidence to help save the Holy Father.