What does Palmer find when her gets home to his room, and what does he decide at that moment?

When Palmer opens the door to his room, Panther the yellow cat is sitting on his bed watching Nipper through the closed window. Palmer realizes Beans has been in his room and placed the cat on his bed. Had Nipper been in the window when Beans was there, he might have killed Nipper. Plmer realizes then he must get Nipper safely out of town and away from Beans and the gang who want to harm him.