They approached closer to it. It was not like any log cabin they had ever seen, consisting, as they could see through the open door, of but one room.
"It's probably only a hunter's lean-to," said Betty. "Don't go too close, Amy."
But Betty spoke too late. Curious to see the whole interior of the cabin, Amy stepped across the threshold. A moment later she heard something move behind her. She turned, but not in time.
An instant later a raised, sliding door of heavy logs slid down in grooves, and Amy was a prisoner.
"Oh—Oh!" she cried out. "What has happened?" and she beat on the heavy logs with her little hands. "Oh dear!"
"It's a trap! You're in a bear trap!" cried Betty. "We must go for help!"
CHAPTER XVI
TROUBLE
The girls were stunned for a moment. After Amy's first frantic cry, and Betty's realization of the danger, and the way out, there came, as there often does following a shock, a period of lethargy.