This was a fun read. It helps if you aren't picky about scientific explanations and are able to accept things because they just are in this so-similar-to-our world. Time travel - it can screw with your brain if you let it. *LOL*
So this, the first of The Chronicles of St. Mary's was a little reminiscent of the Parasol Protectorate series in that it's a light-hearted romp with engaging, larger-than-life characters doing impossibly heroic things. :) It takes place in current London, however, not steampunky Victorian London and there are no (so far anyway) werewolves or vampires. Just time travelling historians and possibly a muse.
The characters are fun and easy to like and the bad guys are very easy to dislike and the action is quick, the story moving along quite nicely. This first book in the series comes to a nice ending - no real cliffhangers to speak of, which made me happy. :) Abrupt cliffhangers annoy the hell out of me.
Oh yes, and there's a bit of romance to go along with the adventures.
Will I continue with the series? Yup, it was fun. :)