Augustus cut him off. “Balcourt’s mistress is an informer of the Ministry of Police.”

It took Horace a moment for the words to register. “Is she?” He seemed more intrigued than alarmed.

De Lilly’s insouciance set Augustus’s teeth on edge. “Madame Perdite is just one of thousands, but any one of those, no matter how insignificant they may seem, can be your downfall. A landlady, a chambermaid, the boy who holds your horse. Fouché has half of Paris in his pay.” An exaggeration, but not by much. “Say nothing in front of anyone, not even the servants. Particularly not the servants. Do you understand?”

Horace nodded, but Augustus could see he didn’t understand, not viscerally, not in that place in one’s gut that shouted danger long before the conscious senses perceived a threat. Horace had been a boy during the Terror, an adolescent in the safety of London. He had no memory of the stench of blood and sweat, the buzzing of the blood-gorged flies in the Place de la Concorde; he had never spent a night in the damp-walled hospitality of the Conciergerie, never heard the screams of a man being put to the question as he moved from begging for life to praying for death. The prisons of Paris were just names to him, names and blank facades; he had no real understanding of the true nature of the terrors within.

This was what happened of hiring boys who were still wet behind the ears and sending them out into the field with nothing more than a few vague instructions and a slightly outdated map of central Paris.

Augustus preferred not to address the fact that he had been equally amateur when William Wickham had first recruited him for covert operations, fresh out of Cambridge. At the time, he had been an aspiring poet by vocation, a fledgling clergyman by necessity, resigned to the prospect of taking a parish and sandwiching verse between his sermons. His encounter with Wickham had changed all that.