Grover is so frightened by the title, he does everything within his power (and then some!) to keep you from turning the pages, in great fears of the monster at the end of the book. But at the end of the book, Grover is the only one left, and he then realizes that he himself is the monster at the end of the book and he had absolutely nothing to fear at all!
It’s a cute story with a great message on the High Holidays when many people fear the Machzor, the lengthy prayerbook used on Rosh Hashanah and Yom Kippur. Like silly Grover, we come up with all kinds of mind-games and excuses and day-dreaming and shenganingans to deal with our fears of it and avoid getting into it as much as can and should.
But hey – the truth is that prayer is a journey of self-discovery! By investing in our prayers, putting ourselves into it, instead of holding back, we learn much more about ourselves. Like Grover, we can find out that what’s at the end of the Machzor, is not our fears, but a better version of ourselves, a deeper perspective, a new understanding of who we are and where we can reach.