Henrietta "Hal" Mortimer has been working with England's operatives and spies for years, her remarkable memory and artistic talents invaluable to many missions. The last thing she expects is to be pulled into a field mission herself, and to be partnered with the most insufferable asset she has ever met. Worse, then, that she has to marry the man.

And the mind of Sphinx...

There are very few people who rattle John Pratt, gifted code-breaker for the Crown, but Hal Mortimer was one of them. Marrying her in order to go into the field for their mission in Paris would be torture, but they had no choice. Will their mutual spite doom their mission before it starts or can they set it aside and work together for the safety and security of their country?