Pet detectives Marlowe and Purrlock are on the case again after an astronomer takes a tumble during The Night of the Comet - and it turns out this accident might not have been an accident at all. When their nemesis, Meowiearty, asks them for help on the case, Purrlock and Marlowe (well, mostly Purrlock) are suspicious, but soon the facts of the case win them over. Dr. Tortuga is a brilliant astronomer, but on the night that should hold the discovery of her career - she instead finds herself in a terrible bicycle accident! But as Purrlock and Marlowe discover, someone's been tampering with her bike! Could it be the doctor's overworked assistant? The disgruntled neighbour? Or the kid who was able to claim discovery of the comet in Dr. Tortuga's place? Come along with the two best detectives in town to find out!