What did Jess make May Belle promise in Bridge to Terabithia?

In "Bridge to Terabithia," Jess makes May Belle promise to take care of their dog, Prince Terrien, if anything were to happen to him. This promise highlights Jess's protective nature towards his younger sister and underscores the bond they share. It also reflects Jess's growing sense of responsibility and the weight of his fears regarding loss and the challenges of growing up.