Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Foreboding
Reading this book is like watching The Ring or The Cabin in the Woods: You can't put it down, but you're also scared to keep reading. Why? The tone of Cooper's writing is the equivalent of that slow, dramatic music seeping into the background of a thriller movie; you just know something bad is about to happen. Don't believe us? Consider this passage:
The Walker stared at him like a doomed man, and now in the pointed, lined face Will could see clearly the traces of the small, bright man Hawkin, who had been brought forward out of his time for the retrieving of the Book of Gramarye, and had through the shock of facing death betrayed the Old Ones to the Dark. He remembered the pain that had been in Merriman's eyes as they watched that betrayal begin, and the terrible certainty with which he had contemplated Hawkin's doom. (10.5)
We get chills just thinking about Merriman's eyes or the Walker's doom—these ominous little words and images keep the creep factor up in the book, even when Will isn't directly dealing with the Dark. It's like it's always lurking around the corner. Which of course it basically is. Eek.