The Cat Who Wasn't There - Lilian Jackson Braun

Qwill agrees to join his beloved Polly on a group tour of Scotland to keep her safe from the Pickax Prowler. On their sixth day in Scotland, however, the tour organizer--Polly's best friend Irma--dies of an apparent heart attack, and Qwill suspects foul play. Koko and Yum Yum may have been miles away from the scene of the crime, but they're just a whisker away from cracking the case. In this mystery in the bestselling Cat Who series, Jim Qwilleran takes a trip to Scotland and brings home a case that only his cats Koko and Yum Yum can solve... Qwill's on his way to Scotland--and on his way to solving another purr-plexing mystery. But this time, Koko's nowhere near the scene of the crime. He and Yum Yum are back in Pickax, being coddled by a catsitter...but Koko won't sit still once Qwill's traveling party returns--minus one member. He's behaving oddly, and Qwill knows what that means: Koko may have been miles away from the murder scene--but he's just a whisker away from cracking the case