The search for stolen jewels and a missing woman yields deadly trouble for an LA detective duo in this hard-boiled mystery by the creator of Perry Mason.   Side by side, Bertha Cool and Donald Lam make quite the odd couple of private investigators. She's a fifty-something-year-old widow, built like a bulldog, with the personality to match. He's a wiry, ex-lawyer in his thirties with a lightning-quick wit that always helps him out of a jam, including the one he finds himself in with their latest case . . .   After Dr. Milton Devarest discovered his wife's jewelry stolen from their safe, they noticed his wife's secretary was also missing. Certain of what happened, Devarest asks Bertha and Donald to locate the secretary and persuade her to return the jewelry, no questions asked. But when Donald heads to Devarest's home to get some answers, all he finds are more questions--and a body . . .   "The best American writer, of course, is Erle Stanley Gardner." --Evelyn Waugh   "Gardner has a way of moving the story forward that is almost a lost art: great stretches of dialogue alternate with lively chunks of exposition, and the two work together perfectly, without sacrificing momentum." --Booklist