Eleven-year-old Zoe is the black sheep of her eccentric, intelligent family. Her older brother is a math genius, her older sister is a talented performer, but Zoe is just plain Zoe. The tipping point comes when her best friend discovers her own talent as a performer and ditches Zoe for the popular theater crowd at their intense Brooklyn private school. Feeling alone, Zoe starts to slip in her classes, and her creepy principal puts her on probation. While all this is happening, an odd new student—a supposed code-reading genius—starts paying attention to her. At first she resists the friendship, but eventually finds that she and Lucas have a lot more in common than she thought and discovers her own unique talent as a code-reader. It’s hard to imagine that the sweet, somewhat spacey Zoe is truly a budding cryptanalyst, and in the same vein the predictable, perky prose doesn’t quite measure up to the unique subject matter. Not seamless, but entertaining and educational. A key to the ciphers embedded in the story appears at the end, along with a list of sources. (Fiction. 8-12)