An odd couple of detectives descends on New Orleans to search for a missing heiress in this hard-boiled mystery by the creator of Perry Mason.   Bertha Cool is a bulldog of a woman with an attitude to match. Donald Lam is a handsome ex-lawyer who makes up for in brains what he lacks in brawn. Together, they're an unlikely pair of private detectives on a mission to find Roberta Fenn, a missing model and heiress in New Orleans. It's a seemingly simple case of lost and found . . .   Except, Donald can't help but wonder why someone would hire a firm out of Los Angeles instead of one based in the Big Easy. Also, locating Roberta proves surprisingly effortless. Keeping track of her is not. She disappears, leaving a body behind in her apartment. Now Cool and Lam must find Roberta and a killer, before someone makes them disappear as well . . .   "Cool and Lam are an amusing and endearing pair—perfect foils for one another." —Monica Muller, 1001 Nights: The Aficionado's Guide to Mystery and Detective Fiction   "No one has ever matched Gardner for swift, sure exposition." — Kirkus Reviews