Book excerpt: Middle school is full of new challenges for Jackson, Gig, Isaac, and Diego, four sports-loving friends who have always stuck together. Lockers that won't open, older (and bigger) kids, classes that are far apart, tons of homework—there's a lot to get used to. One thing the boys are looking forward to, however, is making the football team. Not every one will get what he wants, though, on the field and at home.