一个11岁的小男孩，马蒂，来到了一个新的中学。在他们班里，马蒂的父母是唯一一对在一起的家长，其他同学的父母都已离异。马蒂想跟其他同学一样，于是他想方设法的搞怪，破坏他父母的感情，让他们分开。

What brings best friends together? For Daphne, Velma, Fred, Shaggy and Shaggy’s spunky pup Scooby-Doo, it’s a mystery! The feature-length live-action Scooby-Doo! The Mystery Begins original movie takes you back to when four teenage sleuths (plus one dog detective) first met. Unjustly accused of staging a spooky practical joke plete with ghosts, the kids are suspended from Coolsville High. To clear their names, they team to solve the supernatural mystery….and head straight into nonstop laughs and adventures. Special fun, special friends and extra-special effects make this “how-it-all-began” story - from boy-meets-dog to the first trip in the Mystery Machine and more - a doggone great time!

TheoneweekendwhenMr.Mollishomealonewiththekids,absolutechaosbreaksloose.WhileworkingovertimeinthechocolatefactoryMr.Moll´skidsgetintoafightwiththeneighbour´skids–afightsurroundingsweets,homeworkandthemostfamous

又是一年暑假，顺利结束七年级学业的格雷格·赫夫利（扎克瑞·戈登 Zachary Gordon 饰）已经作好规划，首先狂玩电动游戏，然后抽空和霍莉·希尔斯（佩顿·利斯特 Peyton List 饰）发展一下关系。当然热爱运动的老爹弗兰克（史蒂夫·赞恩 Steve Zahn 饰）并不认同他的死宅计划。受不了父母花样百出的暑期安排，格雷格和死党罗利·杰佛森（罗伯特·卡普荣 Robert Capron 饰）参加了乡村俱乐部，令他喜出望外的是霍莉竟然也在此地，当然还有强硬霸气的佩蒂（Laine MacNeil 饰）。此后不久，谎言被揭穿的格雷格被迫把老哥罗德里克（戴文·博斯蒂克 Devon Bostick 饰），惹出不少的笑话。周旋于野外训练营和乡村俱乐部，初中时代最后一个暑假拉开序幕……
本片根据美国作家杰夫·金尼（Jeff Kinney）的同名畅销儿童系列读物改编