Some Sailors Never Die - Monsters and Mayhem, #3

Take cruiseSee weirdosFight evilAlmost a year ago, Richard and Stanley escaped a nest of supernatural creatures posing as nurses at their retirement home. Together with Richard's granddaughter Burke, they've crisscrossed the country on a mission to protect humanity from the things that go bump in the night, but Stanley's had some mishaps along the way that have left him weak and weary. Burke suggests that a cruise might be just what the doctor ordered, and the two men go along with her plan.
But evil never takes a vacation. From the moment they board, Richard suspects something is amiss, but Stanley is too tired to care, and Burke doesn't believe him. When passengers start dying mysteriously, he's forced to take matters into his own hands, but can he escape the eyes of an over-attentive activities director, a waiter who takes his job far too seriously, and a wealthy widow who's determined to win him over long enough to find the monster and destroy it before it kills again?