"Commander (Retired) Kirby Calloway and his new wife Senior Special Agent (Retired) Ellen Cortez are happily settled on their ranch northwest of Fort Worth,Texas [when] they receive a call from their old friend CIA Deputy Director Kenneth Broussard, aka, Katanga. He wonders if life on the ranch is getting routine, and if they would be willing to travel to the Greek island of Santorini as tourists on his nickel. He wants them to investigate some unusual activities by Islamist illegal immigrants on the nearby island of Sikonis."