All chapters

The Mystery of Cabin Island · Chapter

The Chimney explained

The boys spend uneventful days on Cabin Island, with Frank still puzzling over the cipher from Sparewell's notebook.

What happens

The boys spend uneventful days on Cabin Island, with Frank still puzzling over the cipher from Sparewell's notebook. After a stormy night where Chet notices a crack in the chimney, the boys go iceboating while Joe stays at the cabin. Joe spots a mysterious figure among the rocks and fires a signal shot. The others return to find the intruder gone, and they search the island. Frank discovers fresh footprints and tracks the man, eventually identifying him as Hanleigh.

Themes in this chapter

  • Mystery and Detection

    Frank's ongoing struggle with the cipher and the search for the mysterious intruder highlight the detective work.

  • Resourcefulness and Courage

    The boys coordinate a search, with Frank tracking the intruder through the snow despite the wind and cold.

Characters to notice

  • Frank Hardy

    Continues to puzzle over the cipher; leads the search after Joe's signal shot; tracks and identifies Hanleigh.

  • Joe Hardy

    Stays at the cabin as cook; spots the intruder and fires the signal shot; stays behind to guard the cabin during the search.

  • Chet Morton

    Notices the crack in the chimney; joins the search on the northern side of the island.

  • Biff Hooper

    Explores the southern side of the island during the search.

  • Mr. Hanleigh

    Identified by Frank as the intruder lurking on the island.

Key passages

  • In spite of Joe Hardy's predictions that the marauder would be back for his notebook, that afternoon and the next day passed uneventfully on Cabin Island.

    Contrary to Joe's expectation, the thief did not return for the notebook, and the following days were quiet.

    Sets up the calm before the intruder's reappearance.

  • Crack! Sharp and clear, the sound carried through the winter air.

    A sharp cracking sound echoed across the winter landscape.

    Joe's signal shot alerts the others to the intruder.

  • He heard a crackle of branches. Someone was moving about among the trees, only a few yards ahead. Frank peeped out. He saw a dark figure emerge from behind a clump of evergreens.

    Frank heard branches snapping nearby and saw a dark figure step out from behind some evergreens.

    Frank's discovery of Hanleigh on the island.