Solid paranormal set-up, with a satisfying array of different groups to knock against each other. The book is fairly short, but the "Mals," God's Fist, Spectr, NHEs are all well-conceived and efficiently established. The two leads were also promising, though I will need the future books to feel like I really know them. Gray is already fantastic, however, the fictional equivalent of a scene-stealer--I can definitely envision some pretty funny and crazy developments in the future for poor Caleb who is forced to carry around this quirky, rather opinionated presence inside of him.
Altogether a good beginning. I will definitely continue with the series.