The Schwa Was Here by Neal Shusterman

This book was recommended by a friend, and I gave it a rating of  four out of five. Antsy Bonano meets a "new" friend named Calvin Schwa, although they've been sitting next to each other in Science all year. Most people have difficulty seeing the Schwa and don't even realize he's standing right next to them. The boys even start making money by using his ability to be virtually invisible. Then, the boys get caught breaking into the house of a mean, old man, and their lives are changed. Instead of having the boys arrested, he forces them to do jobs for him.

The Schwa's ability to be "invisible" makes the plot unique. The boys scientifically test this power, which leads to other antics. The plot changes as Calvin becomes depressed; he wants to find out the truth about his missing mother. This problem gives the book a theme. I don't really like the resolution of the plot, but I get it. Overall, it was a fun book to read.