When the Alden children discover that the town council, led by Ms. Lerner, is ready to tear down Greenfield's historic firehouse in favor of a modern building, they try to save it. But mysterious things start happening--objects disappear, false alarms sound at the firehouse, and a strange man appears in town. Luckily, the children find a blue notebook that is just the clue they need to solve the mystery.

שם הספר
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