Lillian Jackson Braun never seems to run out of ideas for her popular series of mysteries featuring journalist Jim Qwilleran and his feline cohort, Koko. In this latest, The Cat Who Tailed A Thief, Koko again exhibits his preternatural intelligence by trying to tip off Qwilleran to important clues to a murder. That Qwilleran is not possessed of the same mental acuity as his cat is what makes this series work. Braun may not be noted for refined prose, perceptive characterizations, or stunningly original plots, but what she does do well is cats. Fans of felines in general and Koko in particular will find this book, the 19th in the Qwilleran series, almost as irresistible as, well, catnip. Some would even say it's purr-fect.