Jessica and her family have just moved from Chicago to the small town of Bixby, Oklahoma for her mother's work. Her first day of school was honed her intro speech to a fine art, though she never says aloud that the water tastes odd. Well, not until she meets Dess in her Beginner's Trig class. Dess is some kind of trig whiz, a little odd but nice, at least until she starts being weird about dreams - she says the water doesn't just taste funny but also causes odd dreams. Jess's been too tired to dream, and says so.
That night she has an amazing, vivid dream - she discovers a world lit by an eerie blue glow, and the the air is full of perfect little blue diamonds. When she explores, Jess discovers that the diamonds are actually rain, and that the whole world is frozen, immobile until she interacts with it.
When Jess wakes the memory of the dream stays with her - until she gets out of bed and steps on wet clothing.
Jess learns that she's a Midnighter, one of the few born in the second of midnight. In Bixby - and possibly other places, they don't know - Jess, Dess and her friends Rex and Melissa, have the ability to go anywhere in town, and see things nobody else can see. Including the terrifying, shape-shifting slithers and the entirely more frightening and intelligent darklings. The slithers usually leave Dess and her friends alone but are intent on harming Jess.
The Secret Hour, first in a trilogy, sets up a plausible universe with interesting and imperfect characters. There are a number of questions that are left dangling for the next installment, wihtout being irritating. - Alex