There is a lot of things that could potentially undercut this thriller. Do we really need another Christianity is a big lie protected by powerful forces story (with a feminist bent no less)? As with so many thrillers, it requires a very high level of suspended belief and the characters are not particularly deep nor is there much literary flair involved.

On the other hand, it is pretty entertaining. What makes it entertaining, IMO, is the fast paced plot and the suspense not the underlying mythology. Toyne has a unique hook, a monk's very public death after jumping from the Citadel in Turkey, and then builds a rather traditional thriller off of that (conspiracy theories, good versus evil, race against time, moles or double agents, civilization at risk, etc.) hook. The unique setting adds flavor but I don't think the rather silly conspiracy theory at the heart of the story adds much. In fact, the conclusion was so over-the-top for me that it left a bad taste in my mouth after having raced to the end.

As noted, there are some rather far fetched aspects to the story, and the plot is not airtight by any means, but if you just sort of give in to the flow and enjoy it - it works. There is enough action and suspense, and the plot moves quickly enough, that can get swept up in finding out what happens no matter how improbable. There are a number of moving parts and side characters with different motivations that work together like a puzzle. Each side is racing events even as they battle each other. The short chapters jump from one side to the other unraveling motivations, throwing up further hurdles and keeping the reader guessing.

So if you enjoy the thriller genre, I think you will enjoy this take on it even if you are not sympathetic to the mythology or find the plot believable.