Fifth in an appealing series of early chapter books about two close friends, boy and girl, whose names reflect their characters' reversal of stereotypical roles. It's Pinky who is anxious about going to his first sleep-away camp, while Rex is busily practicing ball with her dad; still, Rex's last-minute admission that she also has qualms and is counting on Pinky to keep her from getting too scared is just what's needed to start him packing in earnest for what proves to be a wonderful time at camp. Howe presents these young children learning how to share their feelings with a sure touch for realistic dialogue; Sweet's full-color illustrations, on almost every page, nicely reflect the story's warmth and gentle humor. (Fiction. 5-8)