'G-d wears many masks. And one is Groucho Marx," a narrator of Mel Waldman's daring and profoundly thoughtful novel declares. It is a clue and testimony to the threads of humor and irony that weave through this tale of erotic encounter, romance, insanity and murder. Ranging from the neighborhoods of Brooklyn to Manhattan's Bleecker Street with stopovers at Kennebunkport, Maine, Dr. Waldman composes a dark and at times tender and moving fantasy of a modern day Odysseus's quest for mental stability and love. Who Killed the Heartbreak Kid? is that rare mystery novel less concerned with whodunit...