I've had time to think, and I've remembered that I can't make my hero too proactive. There must be a time in the middle when he decides things have gone back to normal, even though the reader can pick up evidence that the villain is still active behind the scenes. Why? Because the hero's single-minded focus on his work, in this plot, will be his potential ruin. It has to end up putting him and those he most cares about in danger, because, as he admits at the end, "I just didn't want to know."
Actually, my heroine is the more proactive of the pair. So proactive, in fact, that my latest beta reader accused her of superheroics at the story's point of crisis. No, sorry, that's staying in. Her issue is wanting to be in control and thinking everything is up to her. Yeah, she'd do what I have her do . . . but it worries me that that beta didn't see it that way.
More rethinking, more rewriting!
My erstwhile beta reader told me that for my novel properly to fit the Suspense genre, I need to have scenes from the villain’s point of view, so the reader can worry about the awful things he has in mind for the protags and feel all the delicious frustration of not being able to warn them against it. ("Delicious frustration" is how I sum it up, BTW.)
I don’t dispute that this can be a good way to proceed. But for this novel, it ain’t happening. A) Because the book’s too long as it is, b) because I don’t want to get my mind too deep and dirty into that racist SOB’s plans and schemes, and c) because said plans and schemes involve way more people than just my protags, and it’d really get off topic if I showed him masterminding the whole nefarious plot. Besides, I don’t want to reveal the scope of the whole nefarious plot to the reader until the last part of the book. I want him or her to be uneasy . . . even though he’s not sure what he's uneasy about.
However, I definitely want to keep the reader aware that the villain is still working away against the protags, even after they’ve come more or less safely through his initial campaign against them. To that end, I’ve added a few lines to a couple of otherwise-innocent scenes, that will make it obvious to the reader that the male protag, at least, is being watched, tracked, followed, and cased out— even if at this point he’s not actually being harmed. Hopefully that will keep the ominous note going underneath, even when the main theme of a scene may be cheerful.