"The Black Hawk" by Joanna Bourne

This novel should have been named after the heroine, not the hero, since it is more her story than his.  Adrian Hawkhurst ("Black Hawk") and Justine DeCabrillac ("Owl") meet in Paris in 1794 when they are 13.  Both are orphans learning the spy trade during the French Revolution.  He's the son of a British prostitute and unknown father, and her French aristocratic parents were murdered two years earlier after which she was horribly abused.  Hawk ends up working for the British intelligence while Justine spies for the Police Sècrete.

Their story is told in flashbacks through their various meetings to 1818 London when someone stabs Justine with a poisoned knife a few blocks from Hawk's home.  Although they haven't met in three years, he helps her recover and together they go after her attempted assassin.

This was different from any other historical romance that I've read.  Justine and Hawk both risk their lives for their countries, sometimes fighting for the same cause and sometimes not.  Their love for each other is not all consuming, but is one of the few constants in each others lives.  The writing is descriptive in unusual ways, and both characters are jaded but not hopeless.  I'd like to read more by this author.  304 pages.