The cat who turned on and off - Lilian Jackson Braun

Jim Qwilleran's latest commission is a piece on Junktown - a ghetto of antique dealers and collectors living in genteel decay. Enchanted by Junktown and its delightfully bohemian inhabitants, Qwill finds himself digs in the area, renting two rooms to share with his sleuthing Siamese companions Koko and Yum Yum. When his landlord C.C. Cobb, one of Junktown's leading citizens, falls mysteriously to his death, Qwill's famous whiskers begin to twitch. It's only when Koko develops a passion for tape-recorders, to rival even that of his journalist mentor, that the vital clues begin to drop into place...