I grew up devouring mystery books, and I still remember the thrill of uncovering clues alongside my favorite characters. For middle schoolers, 'The Westing Game' by Ellen Raskin is a classic that never gets old. It's packed with puzzles, quirky characters, and a twisty plot that keeps you guessing until the very end. Another great pick is 'Chasing Vermeer' by Blue Balliett, which combines art, codes, and a dash of adventure. If your kid loves a spooky vibe, 'Lockwood & Co.: The Screaming Staircase' by Jonathan Stroud is a fantastic choice—ghost hunting with a team of young detectives? Yes, please! These books are perfect for budding sleuths who love a good brain teaser.