Secret Histories follows the Simon R. Green formula. If you like the formula, you'll like this first entry in the series and perhaps all that follow. The setting is alternate-London, and the conceit is a group of "Droods" keeping the world safe with a bunch of magic and tech. Strong protagonist, stronger but less wise female sidekick, insurmountable odds that you're never worried that the protagonist isn't up to. It's fun, but paint-by-numbers.