"Greg Heffley tells about his summer vacation and his attempts to steer clear of trouble when he returns to middle school and tries to keep his older brother Rodrick from telling everyone about Greg's most humiliating experience of the summer. Whatever you do, don't ask Greg about his summer vacation. As he enters the new school year, he's eager to put the events of the past three months behind him ... and one event in particular. Greg knows that...

Back in middle school after summer vacation, Greg Heffley and his older brother Rodrick must deal with their parents' misguided attempts to have them bond.

"Mejor no preguntarle a Greg qué tal lo ha pasado durante las vacaciones de verano, porque no quiere ni oír hablar del asunto. De hecho, al empezar el nuevo curso Greg está deseando olvidar los últimos tres meses de su vida, en particular cierto acontecimiento... Por desgracia para él, su hermano mayor Rodrick lo sabe todo sobre ese incidente que él querría enterrar para siempre. Y es que todos los secretos acaban saliendo a la luz... Sobre...