More bright, knife-edge humor from the author of The Summer House Loon (1979), this time in a more earnestly juvenile story of the four Harris children and their scheme to keep Granny out of a nursing home. We are introduced to the Harrises through the family doctor's eyes, in a splendid, unflattering opening scene that makes the kids look like ill-bred gluttons and their mother, ""the beautiful Natasha,' a slovenly and heartless monster. Harry Harris, the kids' father and Granny's son, is no more sentimental: ""I've found a use for her at last,"" he says of his mother at one point. ""We'll prop her up in the front window to frighten off the Avon Lady."" The project, conceived by Sophie as a joint social-studies effort but carried out more resolutely by the single-minded Ivan, will be an uncensored record (complete with ""charts and appendices"") of one family's problems with an aged member. Ivan's plan is to blackmail his father, who teaches at the same school: he'll hand in these scandalous revelations unless the parents agree to keep Granny at home. (The two younger children, resentful of their lesser role, are to back up the effort with nightmares about an incarcerated Granny.) But Sophie, and readers too, begin to sympathize with the middle generation that must cope with soiled sheets, irrational middle-of-the-night demands, and disapproving looks from strangers at the polling place who think Dad is forcing Granny to vote his way when it's really she who's insisted on coming along. And when Mr. Harris agrees to Ivan's demand on the condition that the children take over Granny's care while the parents go off to dancing, woodshop, and language classes, Ivan finds himself with a full-time job. But he proves devotedly attentive to Granny, and when she finally dies it is he, who had seemed the ""fanatic"" with noble ideals and no feelings, who feels it hardest. Fine stoops to a too-pat and too-shallow resolution in Ivan's ultimate, premature decision to become an industrial organizer--the end result of his troubled mulling over feelings vs. ideals, revolution vs. small improvements. But this is not central to the story, and overall her sparkling rendition of the kids' subversive scheming is a perpetual delight.