Adjusting to a new sibling would be one thing, but Adam, who has lived alone with his parents and then, after their divorce, with just his mother, is disgruntled when Dad returns from England with a new wife and stepdaughter and asks Adam to look after the girl, Sproggy. ""I'm very fond of her,"" says Dad. But Sproggy, who's Adam's age (going on eleven) but looks older and wiser, doesn't seem to need looking after, and she adds insult to injury by practically taking over his friends and his club. Still, Adam resists when ""friend"" Charlie, the handyman at his East Side apartment building, suggests that Adam is finding it hard to share his father. Things do work out between the two ten-year-olds of course, and Greene ends with Adam, Sproggy, Charlie, and Charlie's wheelchair-bound wife Millie at a select party on the lawn of neighborning Gracie Mansion--territory that Adam had thought was only for ""big shots."" And Charlie and Millie, who were invited as representative night school students, find the occasion ""the high spot of their lives."" Charlie himself, like his presence at the party, is a good old-fashioned land-of-opportunity cliche, and he goes on a bit too much about the greatness of America and the pleasures of night school--but his proletarian good nature will get him by. There's a steady stream of amusing touches, and Greene knits the different strands of Adam's story with agreeable ease.