Greg tries to tell his principal that someone found his balloon, but the principal will not give Greg the prize until he actually brings the balloon to school as proof. Luckily, Greg’s mom wants to take Greg to Maddox’s house for a get-together. Greg agrees, seeing this an opportunity to get his balloon back. Unfortunately for Greg, Mrs. Heffley and Mrs. Selsam plan on going into town and leaving the two boys on their own at the house. 

Greg is appalled to learn that Maddox’s mother does not let him eat junk food or watch TV. He finds a huge bookshelf “in the family room…where the TV was supposed to go” (90). Maddox tells Greg that for fun, he usually plays violin or builds Lego sets. Greg is relieved to learn that Maddox actually has toys. Maddox has a gigantic Lego city in his room, which blows Greg’s mine. However, Maddox will not let Greg play with the Lego sets, and instead gives him the leftovers bin, which is “filled with a bunch of random pieces” (92).

A while later, Mrs. Selsam and Mrs. Heffley return. As Greg and his mother are leaving, Greg sees his balloon sitting on the dining room table and grabs it.