In Irish Milkshake Murder by Carlene O'Connor, Tara and Danny are on a ferry trip to Inis Mor, where passengers enjoy boozy milkshakes. But someone's turns out to be their final round. In Murder Most Irish by Peggy Ehrhart, St. Patrick's Day is drawing near and folks at Hyler's Luncheonette are getting into the holiday spirit with a festive green milkshake. It's a hit, until a patron is felled by one of the frothy concoctions. In Mrs. Claus and the Luckless Leprechaun by Liz Ireland, Claire whips up some minty milkshakes for her ice cream shop, but the promotion makes one elf the target of a decidedly unlucky strike.