Kyle Keeley is the class clown and a huge fan of all games—board games, word games, and particularly video games. His hero, Luigi Lemoncello, the most notorious and creative gamemaker in the world, just so happens to be the genius behind the construction of the new town library. Lucky Kyle wins a coveted spot as one of twelve kids invited for an overnight sleepover in the library, hosted by Mr. Lemoncello and riddled with lots and lots of games. But when morning comes, the doors stay locked. Kyle and the other kids must solve every clue and figure out every secret puzzle to find the hidden escape route!

凱兒．奇力是班上的丑角，也是個遊戲迷，不論是桌上遊戲還是字彙遊戲，他都喜歡，對電玩遊戲更是情有獨鍾。他的偶像——路基．雷孟伽洛是世界上最惡名昭彰又充滿創意的遊戲發明王，也是鎮裡新建圖書館的幕後天才。在雷孟伽洛主辦的解謎遊戲中，幸運的凱兒和另外十一位孩子一起勝出後受邀至圖書館過夜 ，贏得人人羨慕的冠軍寶座 。但是，天亮後大門依舊深鎖，凱兒和其他孩子，必須找出每個線索，才能破解神秘的謎題，發現隱藏的脫逃路徑。