Agatha Christie covers terrified and delighted me as a kid (there were a bunch of reissues whose covers were based around the idea of "take an English scene whose details may or may not have anything to do with the story and drench it in bloodstains and skulls").

Re Cal - well, certainty is the first step, and a big one. Also, not to be too flippant but if he's on the spectrum he's pretty much normal for our social circle. And at least he's been born into a time when society's getting a little better at dealing with it.