<P> On Halloween, Greg and Rowley go trick - or - treating, but are challenged by teens who spray Greg and Rowley with a water - filled fire extinguisher . Greg tries to threaten them by saying he's going to call the police, but the teenagers start to chase them . The two friends escape and go to Greg's grandmother's house until the teens leave . </P> <P> After getting few presents for Christmas, Greg decides to play a game with Rowley in which Rowley must ride a bike while Greg tries to knock him off . On one of Greg's tries, the ball gets under the front wheel, which causes Rowley to fall off and break his arm . When Rowley goes to school with a plaster cast, the girls take care of him (carrying his books, feeding him food) which makes Greg jealous . After Rowley's arm heals, he and Greg decide to enroll in the safety patrol program in which they walk younger kids to their homes . </P> <P> One day, as Greg is walking the kids by himself he chases the young children after scaring them with a stick with worms on it . A neighbour contacts the school and tells them about Greg's unusual behavior . The principal suspects Rowley, as Greg was wearing Rowley's jacket . Rowley is suspended from the safety patrol . Greg later decides to confess the truth, but Rowley has already informed on him, resulting in their friendship breaking off . </P> <P> Greg tries to befriend Fregley to make Rowley jealous, although he is uncomfortable around Fregley . Resorting to auditioning for the school play (based on The Wizard of Oz) Greg lands the role as a tree, while Patty Farrel is cast as Dorothy, the protagonist of the novel . During the show's opening performance, Rodrick brings a camera to film the play . Greg becomes too nervous to sing, confusing the other "trees" who also fail to sing . Patty gets frustrated and angers Greg, who throws props at Patty, and then everyone gets in the fight, ending the play in chaos . </P>

Summary of the first diary of a wimpy kid book