“I’d love to kill you sometime,” murmurs a character in “One of Us,” all but announcing the quiet, matter-of-fact evil that will drive him to pursue the book’s protagonists over the next 200 pages.

Charlie is his name. Or, at least, that’s what he calls himself but he also says he’s the uncle of sister-and-brother escapees Eleanor and Bolt and we know for sure that isn’t true. Whatever his name is, he’s a violent criminal who murders strangers as if to relieve an itch, who is casually racist and who wants to possess the siblings because he believes they have supernatural gifts.

That’s also why a traveling circus wants them in Dan Chaon’s novel, which is set in the early 1900s. The adolescent siblings, who are orphans, flee from their uncle’s “care” and fall in with a circus, where their extra-sensory abilities don’t seem unusual when they’re in the company of a little person who is said to be able to tell anyone when they will die, a muscle woman with a heart of gold and a bestial man who has somehow transformed from a huckster into a groaning monster who eats random chicken parts (not for nothing, the title “One of Us,” quotes a line of dialogue from the classic, circus-set film “Freaks”).

If you’re a reader, Chaon is a name you should know. He writes literary fiction, but he’s attracted to dark undercurrents of humanity in a way that will ring bells with Stephen King fans (or fans of Ray Bradbury, who also liked circus settings and who’s one of several writers to whom “One of Us” is dedicated).

Probably because they’re the most vulnerable among us, children are often in danger in Chaon’s books, which include “Await Your Reply,” in which a girl believes she’s in love with her teacher; “Sleepwalk‚” in which an unscrupulous man agrees to deliver a package that turns out to be an infant; and “Ill Will,” which I’d call his best novel. It’s about the aftermath of a massacre and it’s so claustrophobic that it made a friend of mine swear off Chaon forever.

With its creepy setting and matter-of-fact violence, I don’t think “One of Us” is the Chaon book to change her mind. But she is missing out on gorgeous writing like this description of the sibling’s late (and, because this is Chaon, neglectful) mother: “Their mother was a butcher’s daughter with a lovely timid voice, a tinklebell sigh of soft misery.” She’s missing humor like this take-down of the kids’ would-be guardian: “The smell of Uncle Charlie’s breath suggested that he’d had sardines and beer for dinner at a pub, then smoked cigars and drank whiskey for a while, then vomited in a ditch while he was stumbling home in the rain.” And on insights like this one into the darkness in (some) people’s hearts: “Most people expect cruelty as the normal order of things, but for poor Lacis, it is a constant shock, he has always believed in the essential goodness of people.”

Chaon, on the other hand, does not seem to be surprised by terrible behavior. Atmosphere is crucial to his books, and it’s usually a combination of hope and page-turning dread (the first half of “One of Us” is so propulsive that it may be inevitable that the second half lags a bit).

Like all of his work, “One of Us” acknowledges the dark forces that challenge the goodness in his characters. That’s why his books are so gripping: Good and evil are in constant battle and it’s not at all clear which will win.