When thunder shakes Rustwood, secrets begin to stir again… After uncovering the truth about Rustwood’s past and earning their place as the new Guardians of the Gear , Atlas, Luna, and Moose thought the worst was behind them. But during the grand reopening of the Rustwood Museum, a sudden storm traps everyone inside and when the lights flicker back on, the museum’s most prized exhibit, The Heart of Rustwood , has vanished. The deeper they dig, the stranger things get. Hidden rooms. Blueprints that don’t match. Staircases that shouldn’t exist. And a unique power source that may have been more than just a display. As Atlas and Luna follow the trail, they discover a dangerous plan that reaches back to the town’s forgotten past and forward into its uncertain future. Someone wants Elias Flint’s lost technology back. And if they succeed, Rustwood won’t survive the storm that follows. Join Atlas, Luna, and Moose in their most electrifying mystery yet. Where the walls whisper, the storm remembers, and the light might not be on your side.