What are the effects of the scenes of Natty dressed as a bear?

In Chapter 25, Magua enters the cavern and Duncan challenges him to do his worst; Magua says he will gather his tribe and see how bravely those words could be repeated. He boards up one entrance, and prepares to leave by another when the growl of the bear is heard. Thinking it is the conjurer, he waves it aside impatiently. The bear grasps him in a hug, pinning his arms to his sides. Heyward binds Magua completely. The scout reveals himself and gags the new captive. They must get away quickly. Heyward takes Alice in his arms and covers her up. Outside the door of the cavern the relatives of the sick woman wait. Duncan tells them that the spirit has been trapped in the cave and that they are taking the woman away to be strengthened. He says that no one must enter the cave. They disappear into the woods. Alice revives. Hawkeye instructs them to follow the brook to the nearby tribe who will probably give them protection. He will stay to fight for Uncas.