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, she won’t stop talking about them now that they’re out in the open. I still have so many questions, though, like is she still the same woman I always assumed she was? And can I ever fully trust her again?

When Nan refuses 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.