I liked Brandon Sanderson's novella, Legion, more than I did his other novella I read in 2012 - I forget the title, it was the sci fi one about the military commander brothers - namely because the main character here was way more interesting. 
 THe quick of it is that he's a regarding as perhaps the smartest man on earth, but also insane. He points out that he's quite average - it's all the imaginary folks he surrounds himself with that are so smart. He uses his army of imaginary geniuses to solve mysteries. 
 In this case, a man has invented a camera that can photograph the past. But he's gone missing, with the camera, and it's up to our brilliant crazy guy to solve it. 
 The story works for me. I really wanted it to be longer, not because the story demanded it, but because I didn't want it to end. I hope this isn't it for this character. It's free on audible as of this writing. It's hard to say no to free.