This was a nice addition to the series. One of the reviewers on the back cover said it was like James Bond mixed with Simon R. Green's Nightside books, and I think that's a goo description.
The story moves the plot forward and I liked the introduction of Harry and Roger. Green proves he's willing to kill of at least tertiary characters, which is good. I must admit, I didn't really feel a sense of loss at their deaths, but it did make it feel like there were consequences for actions and that things weren't going to work out basically fine just because of something the protagonist did. The world might be saved, but there's a price.