Something More Than Night, by Ian Tregillis

Imagine a sci-fi novel masquerading as a detective mystery featuring a pulp fiction detective (like a Raymond Chandler character or Nick Carter private eye), who happens to be an angel (Bayliss), and a smart new angel protagonist (Molly).   That's the model for this book.

The concept is that the shared frames of references of angels creates a mantle of ontological consistency (MOC) which keeps the cosmos running in an internally consistent fashion. The angels do not, however, want to stick around to keep the system running, but are held in place with an unbreakable link.   One of the angels, Gabriel, is murdered, which leads to Bayliss' and Molly's interaction, which leads to - well all sorts of drama.

Dr. Tregillis, a physicist, let's his training show with a continual flow of obscure references that are more of a conceit than an advantage.  The union of scientific drivel with 1950's dialogue is not pretty:

"Trust a nickel grabber to solve an epistemological problem through the radical application of astrophysics. It's extreme, like re-normalizing the fine-structure constant to swat a fly."

"It smelled like bubble gum and a smattering of elements that lived on an axis orthogonal to the rows and columns of the Periodic Table."

"Naturally the high rollers had claimed the front-row seats. ...The knoll overlooked a narrow sound formed by multidimensional breakwaters of quantum indeterminacy. Slow ripples of mathematical entropy lapped at the shoreline, eroding the non-Abelian symmetry groups along the water's edge into towering pillars of salt." 

This novel is almost amusing.  There is a good twist in the plot which nearly makes it worth sticking with the book in spite of its affectations.

Something More Than Night