One of the things that makes Brandon Sanderson a truly brilliant fantasy write is his ability to come up with unique, original magical systems. 
 And he churns out another one in his young-adult debut: a geometric magical system based on lines and circles, with two-dimensional chalk creatures summoned by "The Rithmatist." The first half is rather slow, but the story blossoms when it focuses on the missing Rithmatic students -- think a combination of alternate history, fantasy and murder mystery. 
 Despite being only a poor chalkmaker's son, Joel is able to attend the prestigious Armedius Academy -- but he spends most of his time thinking about Rithmatic duels, history and strategy. He knows that he will never be a Rithmatist, but he still yearns to study it. When an arrogant new professor turns the Rithmatics department upside-down, he gets the chance to be an assistant to the kindly Rithmatics-historian Professor Finch. 
 But around the same time, students start vanishing from Armedius. Not only are the vanished students all Rithmatists, but the only clue left behind is a chalk marking that no one has seen before. 
 Then the son of a knight-senator is brutally killed by chalklings controlled by "the Scribbler." Suddenly Armedius is the center of political and social strife, and the police are brought in to protect the students who remain. Joel and his oddball friend Melody are quickly enmeshed in the investigation, but even Joel's encyclopedic knowledge of Rithmatics might not be enough to catch the Scribbler. 
 "The Rithmatist" is set it a pretty memorable world -- it's an alternate version of Earth where JoSeun (aka Korea) conquered Europe, South America is ruled by an Aztec empire, and the USA is a vast archipelago of fifty ISLANDS. Also, Leonardo Da Vinci is a steampunk saint (not kidding), and Rithmatics is not just a magical system, but a part of religion as well. 
 The first several chapters are rather slow, though -- Sanderson spends too much time on Joel's obsessions and schoolwork. Not interesting. It feels like he had started the story before fully outlining his plot, world and magic system. But everything seems to click into place once Joel gets involved in the mystery -- suddenly we have a murder investigation tangled up in political machinations, as well as some mysterious magical goings-on (wild chalklings, mysterious signs, etc). 
 Sanderson is a pretty good writer of mysteries, and he knows how to work in plot twist after plot twist. So he deftly weaves together a twisty whodunnit, picking up seemingly unimportant details and weaving them into the greater whole. His writing is strong and smooth, with lots of humor, mostly from Melody (unicorns!), and the occasional moment of sheer horror, such as Joel being attacked by wild chalklings and finding himself unable to scream. 
 And without revealing too much, Sanderson seems to change his mind in the last chapter. It seems like it's going to be a standalone book.... but he throws in some final twists, and opens the door to sequels. In fact, he pretty much guarantees them. 
 Joel comes across as whiny at times, but he's overall a likable hero -- he's strong-willed, smart and obsessed with Rithmatics, and he has to use these qualities to hold his own among the Rithmatists. He's also got a pretty solid supporting cast, especially Melody -- a humorously eccentric rich girl who is Joel's opposite in every way, and so she complements him nicely. There's also the cruel Nalizar, Joel's hardworking mom, and the pleasantly paternal Professor Fitch. 
 "The Rithmatist" has a rather weak beginning, but the brilliant mystery that blossoms later on makes this book well worth reading -- and leaves you hungry for more adventures in the United Isles of America. On to Nebrask!