Greg Heffley is in big trouble. School property has been damaged and Greg is the prime suspect. But the crazy thing is, he's innocent! Or at least sort of.
The authorities are closing in, but then a surprise blizzard hits and the Heffley family is trapped indoors. Greg knows that when the snow melts he is going to have to face the music but could any punishment be worse than being stuck inside with your family?
為了可以收到更多、更好的耶誕禮物，葛瑞很努力表現出「最好的一面」，老哥羅德里克卻一天到晚跟耶誕老公公探員說他的壞話，弟弟曼尼也扯他後腿，更別說葛瑞自己還因為沉迷於電子寵物而跟爸媽借錢――當然被拒絕了！
不得不靠自己賺零用錢的葛瑞，異想天開的揪好搭檔榮利一起辦市集，想當然又闖禍了，而且事情鬧得有點大，還被警察盯上！幸好超級暴風雪來襲，原本以為要亡命天涯的葛瑞因此逃過一劫，和家人躲在家裡。沒想到雪卻愈下愈大，斷電又斷糧，一連串的鳥事讓葛瑞開始考慮要不要去警察局自首？
——中文簡介摘自未來出版出版《葛瑞的囧日記 6：老弟很有事》