It's called the Crimean Wars (I honestly forgot all about it and had to look for it all over again. LOL). This war is actually between the Ottoman Empire and Russia, but because England and France were threatened by Russia's advance, they joined with the Ottoman Empire. I don't think we need to be too accurate with the historical details. The only issue I have, which I only recently realized, is that Crimea is far from England.
Here's a picture:
https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcRiMt_VsC_6DVNRWSIWkVhOieGOeLzo7kUAvVxn9B7u4s9QuqwoZg
This means that if Claire is doing spy work for Russia, it will take too long before the information reaches the right ears. Although for the sake of the story, we can always assume that it won't take too long :) Her goal is to steal military info like how many weapons, men, horses will be deployed, supply routes, technology blueprint, etc. Nick's goal is to intercept all the stolen information/documents and discover who is behind it. My idea is that at one point Nick will secretly suspect her and she might also suspect that he works for the Queen. They'll try to throw each other off track, but she'd be closely watched, then would either be fed with false information with the help of his contacts or her messages will be tampered. Because of that, her employers will think that she's a double agent and will send one of their agents to abduct or kill her. Maybe that will be the point where she walks out of her deal with the Russians and starts running for her life. So their problem will be how to save her from both the Russians and the English law.
This is just me making a suggestion, everything is flexible. Feel free to add or erase or edit anything. :)
