Looks like Green has settled on a format (or should I say formula?) for this effective supernatural series about government ghost hunters. Start with a novella to introduce the characters, keep the cast small, segue into the main story, set it in one location and don't leave it until the end. Fair enough. It worked the first time and it works this time as well.
The small cast of characters is fun: JC the cocky leader, Melody the cynical mechanic, Happy Jack the unhappy telepath, and Kim the ghost, and JC's phantasmal girlfriend, who wants to be a real girl (unofficial member); and their interplay is fun. The menace is interesting, partly because the reader is never quite sure which of the various people and creatures who appear really are the menace -is it a scientific experiment gone wrong, or a creature from the outer darkness, or both? Don't worry, our fearful heroes will find out whether they like it or not. (Hint: just don't trust anyone or anything.)
This is lightweight spooky fluff, ideal for when you're in the mood for light entertainment, spooky or not. I'll be back for the third installment. Chances are you will too.