Alvirah Meehan. lottery winner turned amateur sleuth, and private investigator Regan Reilly are guests, along with their spouses, on the "Santa Cruise?" The cruise is a gift from Commodore Randolph Weed to a select group that "has made the world a better place?' His largesse is prompted by the desire to create a buzz about his new cruise ship,the Royal MermaM, as she sets out on her maiden voyage.……