Fourth grader Mateo Martinez's former best friend, Johnny, begins hanging out with some bike-riding bullies, leaving Mateo high and dry. Thankfully, Mateo finds a new best friend in Ashwin, an American Indian boy who shares Mateo's love for medieval knights and warfare. One night Mateo sees two skunks stealing his sister's trike. Vowing to get it back, Mateo begins his midnight war against the pair of thieves.