I love the way this novella takes the idea — that someone could perhaps look into your mind and take away your memories, at the cost of having to keep them themselves if there was anything distressing in them — and then develops it, runs with it, deals with what a character who could do that would be like, what they would be willing to do, what they’d feel about it. How they could profit from it, and what that might cost them.
The narrator is, of course, unreliable. He’s unreliable even to himself, because he doesn’t know which memories are his, and which memories might be missing. Truth is a malleable thing in this world, because it depends on what you believe, and he can change that. (It never really addresses what happens when someone has some kind of record of what he’s going to wipe.) Identity is malleable too — and his changes all the time as he takes on the memories of murderers and victims. It’s definitely a fertile ground for a story, and K.J. Parker makes great use of it.
This novella has convinced me I really need to get round to reading more of K.J. Parker’s work. He does an amazing job here of creating a character and a complex story from a simple seed — without it ever getting too tortuous.