I wrote this before I realized there already was a review and am too lazy to change anything now. But, between the two reviews, you should be able to get a good idea of the book. I agree with previous comments.

AGENTS OF LIGHT AND DARKNESS- Simon R. Green
This is the sequel to SOMETHING FROM THE NIGHTSIDE. The Nightside is a hidden place in London where darkness, evil, and monsters of all kind, human and otherwise, live.
John Taylor, PI, is often hired to psychically find things there as that is his gift (or part of it.) He's a pretty interesting character. He seems to have inherited strange abilities from his unknown mother. And the few tidbits you find out about her are truly scary. I can't wait to find out the real truth.

AGENTS OF LIGHT AND DARKNESS begins with John finishing off a job; he was hired to quickly find an object and give it to a monster named Jessica Sorrow before she destroys the Nightside looking for it. The meeting itself is very dangerous and fascinating; Jessica has the power to destroy the world.
He witnesses a murder...but doesn't try to interfere. He's not a white knight that needs to save everyone, especially since there aren't any innocent people living in the the Nightside. His only loyalty is to whoever hires him and his few friends.
John's next job is a no choice situation. He's hired by the Vatican to find the Unholy Grail. This is the cup that Judas drank from at the Last Supper. It corrupts all who touch it, but also brings them great power. Needless to say, everyone in the Nightside is after it. And if that isn't enough, merciless angels from above have been sent to take it out of human hands, while the angels from below want it for their master. If John doesn't find the cup before the angels do, the final battle may begin and the end of the world come to being.
This book has monsters you've never seen before. It's a dark and horrifying world at times but a fascinating one too.
I highly recommend it and can't wait for the next. These books are complete in themselves but for the running mystery of John's mother's identity and his trying to stop a possible future he had seen. AGENTS OF LIGHT AND DARKNESS didn't have a romance in it, and I don't know if there will ever be one (though John seems to learn more about his friend Shotgun Suzie

) I think Green may have included romances in his other books, so there is hope. In the meantime, there's lots of action.

Linda