Eleven-year-old Dave is no intellectual. When his Dad gets a summer caretaking job at a scientific research station, his main concern is missing out on his chance to shine in the eleven-and-under baseball circuit. And, as the scientists' families begin arriving with their crates of books, Dave is content with just one: his Guinness Book of World Records. But there is another brain on Quartz Mountain, the one old Professor Botti is growing in his lab. It came from chicken cells, but, through the professor's tutelage, ""It already knows the basics of mathematics and language."" Now Dave, sworn to secrecy, is enlisted to read astronomy to the brain--and, when he becomes bored with that, he switches to sports facts from Guinness. And so it is that Dave, aided by mental messages from the brain, answers enough questions from a local radio quiz to win a baseball bat, a turn on a TV quiz show, and a reputation as a brain himself. All goes well until the brain becomes malevolent, dangerous to the professor and to one scientists's small child whose body it wants to inhabit. . . and Dave, struggling against telepathic temptation, must destroy it. Of course he wins the TV quiz game anyway: ""I hadn't really thought about how much I had learned from those books."" Surely one of Anderson's less ambitious undertakings, this is bright enough to hold its own among the run of large-print, easy-reading adventures.