Cats on a train are so much better than snakes on a plane! Ever feel like your entire world has been turned on its head? That's how I've felt ever since the gang and I found out that Nan has been keeping major family secrets stashed neatly away in the attic. What's worse, we still don't know exactly what happened, and I have so many follow-up questions, like is she still the same woman I always assumed she was? And can I ever fully trust her again? With Nan unable to give me a straight answer, I invite my parents to join me for a cross-country train trip so that we can all discover the truth, once and for all. Octo-Cat hitches a ride with us, too, and it's a good thing he does, because it isn't long before a dead body joins us in the dining car. Now we have two mysteries to solve, and fast-our lives and legacy depend on it.