Some Like It Hot

At the start of Larsen’s entertaining if uneven third mystery featuring Chicago PI Cat DeLuca (after 2012’s Sticks and Stones), a harried-looking Santa Claus on the run from two thuggish grinches turns out to be Cat’s first sweetheart, lovable ne’er-do-well Billy Bonham, apparently now a PI, too. Billy has taken on a case involving a pair of missing diamond earrings and a femme fatale with a brain tumor that soon lures Cat into tackling bigger game than the cheating husbands her Pants on Fire detective agency usually handles. That three sisters write under the Larsen pseudonym may account for the inconsistent tone. The slangy, cartoonish style suits Pants on Fire shenanigans and Cat’s giant family reunions with the cheerful, semicorrupt DeLuca clan, but Larsen spends so much time clowning that more serious moments, like a childhood friend’s funeral, make little impact. The lighthearted treatment of the gruesome climax may strike some as ghoulish. (Mar.)