Crusoe is excited to see the canoes, but he changes his mind. Why

Crusoe isn't excited to see the canoes, he is worried, and when he sees twenty or thirty men, he wonders how he will fight. He spies two "miserable wretches" being pulled from the boat. As one is beaten and cut open for the feast, the other manages to run away, towards Robinson. He fetches his two guns and goes to save "the creature's" life. He manages to shoot the two men pursuing the prisoner.