At some point, a lot of people believe they have an imaginary friend. But what if you had dozens? 
 That's life for Stephen Leeds, the unique protagonist of "Legion," a story very different from everything else that author Brandon Sanderson had yet written. Instead, this novella is more of a blend of quirky urban fantasy and science fiction, although at times the story feels kind of like a dry run for a potential new series. It also has a protagonist who is literally accompanied by a merry band of imaginary friends. 
 Stephen Leeds is known as "Legion": he has many different "aspects" that he hallucinates, each with valuable skills and knowledge that allow him to do almost anything. One is a deductive genius, one is an elite soldier, one is a linguist, and so on. This gives him the skill sets of every person he sees, allowing him to be a rather unique problem-solver for those who can afford his services. 
 Then a woman named Monica approaches him with a very odd mission: find a scientist named Balubal Razon, who has somehow developed a camera that can see back in time. Now he's gone to Jerusalem to find out if Jesus Christ truly existed (although how he would know where EXACTLY Jesus was at any given time is never really explained). So Stephen, Monica and the various aspects set out for Israel. But soon they find that locating Razon isn't their only problem, because a dangerous terrorist group also wants his camera. 
 Brandon Sanderson is a writing machine who seems to brim over with fascinating new ideas, so it's not surprising that "Legion" feels like the springboard for another series, should he choose to pursue it. Of course, it also doesn't feel entirely over at the end -- he wraps up the main plot about the camera, but there's a running subplot about Stephen's ex-girlfriend that is never concluded or even explored that deeply. 
 In the meantime, Sanderson's writing is brisk and swift, with plenty of dryly-humorous conversations between the "legion" of aspects ("I'm not a hallucination. I have state-of-the-art stealthing equipment") as Stephen works through the whole thriller plot. Fortunately, the story is never subsumed under the antics of those aspects, and Sanderson peppers the tale with enough bloody explosive action and mystery to leave J.C. satisfied. 
 But the real draw here is Stephen and his aspects -- it's kind of fun to imagine this guy talking to his invisible friends, who really act like actual people with quirks and dry humor. There's the the elegant elder Tobias, quirky Audrey, hardcore soldier J.C. ("he had the eyes of a killer. Or so he claimed. Perhaps he kept them in his pocket"), and plenty of others. Stephen serves as the long-suffering straight-man whose life is perpetually complicated by the possibly-imaginary people who surround him. 
 While "Legion" feels like a single chapter in a much, much larger story, this novella is a solid little offering by a consistently excellent author. Here's to more Stephen and his possibly-not-imaginary friends.