With the arrival of Mark Herron, an orphan whom the Melendys befriend in their usual wholehearted way, a summer already full of happenings reaches yet another level of richness and fun. "All summer!" said Rush, with his mouth full. "Think of it. All summer long." "All summer what?" Mona wanted to know. "Just all summer," Rush said happily. "I mean this is only the beginning of it. Dams and swimming and the garden and picnics and hot days and all...