In Keeper of the Keys, the final installment of Earl Derr Biggers' beloved Charlie Chan series, the astute Hawaiian detective faces one of his most baffling cases yet. Set against the picturesque backdrop of Lake Tahoe, this gripping mystery is a testament to Chan's unparalleled skills and unyielding determination. When renowned scientist Dr. Harold Riddle is found murdered in his secluded mountain home, suspicion falls on the eclectic group...