We've got your back. With the Tough-O-Meter, you'll know whether to bring extra layers or Swiss army knives as you summit the literary mountain. (10 = Toughest)
(5) Tree Line
While the action is pretty straightforward and we don't expect you to have much difficulty following the main events of the novel, there are a few things that lift The Mysterious Benedict Society beyond Base Camp and bring it to the edge of the Tree Line.
First off, Mr. Curtain's plot is quite convoluted and somewhat challenging to thoroughly understand. You might need to reread a section or two to really get what he's up to, how he got to this point in his plan, and exactly what the Improvement would mean if it actually happened.
Second, there's a boatload of wordplay that could be easily missed by a casual reader. It takes a more astute student (an astudent?) to catch some of the cleverer puns, look up a word or two, and get the full meaning of Trenton Lee Stewart's words.