Well, well, I'd hate to predict a Highsmith novel because it is impossible, but I think I can see where this is going.
I believe that so far everything that has happened to Arthur is Highmith being a vengeful goddess, who loves messing with her characters, and making him regret a moment when he felt contentment on page 13.
Now, Arthur's life is unraveling like that of Job.
I'm kinda hooked.
Rage, Arthur, rage against the author!