Zachary Gray - The Moon By Night

In The Moon by Night (1963, ISBN 0-374-35049-3), Vicky Austin and her family are on a cross-country camping trip when they meet Zachary Grey at a campground. Zach is there with his parents in a luxuriously equipped tent trailer pulled by a brand new black station wagon. As he explains to Vicky, his family is camping its way home from Hotchkiss, the school from which Zachary has just been expelled, presumably for poor grades. Zach then pursues Vicky at other campgrounds across the country. Vicky is flattered by Zach's interest, and intrigued as well as discomfited by his cynical attitude. Vicky's younger sister Suzy and older brother John both heartily dislike him. Vicky's father, Dr. Wallace Austin, deduces that Zachary has a history of rheumatic fever that damaged his heart. Several times, Dr. Austin orders Zach to avoid strenuous exercise as he accompanies Vicky and her family in their sightseeing. Eventually Zach goes missing one evening in a game of hide and seek. As the Austins search for him, Zach lures Vicky to a remote mountainside to speak with her privately. When Vicky tries to return to the campsite and her family, an earthquake causes an avalanche, and Zachary is trapped between some rocks. Before and after help arrives, Zach promises Vicky that he will begin to take better care of himself.