A year ago, the Aiye siblings lost their parents and sister in a mysterious train accident. But when the eerie Ms. Crowe shows up on their doorstep, she reveals that it wasn't an accident at all.
With their sleepy Great-Aunt Victoria reluctantly along for the ride, the kids are plunged into a world of puzzles, secret codes, and hidden dangers. Their father, a famous inventor, left behind his greatest creation-a puzzle only they can solve. But as they dive deeper into the mystery, they start to wonder: who can they really trust?
