I discovered Trenton Lee Stewart while wandering through a bookstore, and I think of that as a very happy accident. His book The Mysterious Benedict Society starts a 3-book series that takes readers on a fascinating journey with some exceptional characters, and started me on a fascinating journey through his books.
Nicholas Benedict is an odd gentleman who has decided to sponsor a team of super-smart kids to conduct a secret mission. Benedict is also incredibly intelligent, but he is limited by his narcolepsy. So he recruits kids through a puzzling newspaper ad which leads kids to an intelligence test, and a few of them to his Mysterious Society. 11-year-old orphan Reynie Muldoon heads up the team of four to infiltrate the Learning Institute for the Very Enlightened to get intel on its leader, Mr. Curtain, who has plans to take over the world.
From this, you can see that this first book has all the makings of a strong middle grade fiction book. But what you learn as you keep reading is that this is a well-written, spellbinding story that pulls you in until the end. The characters are genuine and interesting, and their adventures are fun and exciting. This is a great series of books for anyone who likes Lemony Snicket's Series of Unfortunate Events, Roald Dahl, or (one my all-time favorite children's books) Norton Juster's The Phantom Tollbooth.
Besides these 3 books about the Mysterious Benedict Society, Stewart has also written a stand-alone book that takes you back to Mr. Benedict's childhood and a new one called The Secret Keepers, which came out last fall. I haven't had a chance to read the newest one yet, so it may show up in a blog post later this year. I did read The Extraordinary Education of Nicholas Benedict, and to be honest, I didn't think it was as good as the original Mysterious Benedict Society books. It's interesting, but if you're trying to get kids into the series, I wouldn't lead with that one. But for a fun, smart adventure story for kids (or for grown-ups wanting to feel like a kid again), then I highly recommend The Mysterious Benedict Socety.