So perhaps he is nobody after all. An angry youth: his father’s child. But Livia’s with him, and he must protect her. There could be a blade in the shaft of that umbrella, a gun hidden in those trouser pockets. Lady Naylor appears to sense Thomas’s thought. She speaks to him rather than her daughter.

“It’s like this,” she says. “Either you betray us, and everything stays just as it is. The lies, the sweets and cigarettes, the whole hypocrisy of power. Or we end it all. Send it crumbling into dust.”

“An end to Smoke.” Livia’s voice is thick with something. Hard to say whether it is suspicion or hope. “Is that what you have been working on? A new world of virtue?”

Lady Naylor nods then gathers her daughter’s hands in hers, a scooping gesture, like pushing together the crumbs scattered on a table.

“Yes! A new world of virtue. Of justice. I am doing this for your father.”

Justice. The word is like a call to arms. It triggers a yearning in Thomas. He struggles to contain it.

“What about the child?” he asks gruffly. “Will he come to harm?”

His eyes seek out the shapeless lump of limbs and coat on the stranger’s lap; he thinks of the scratching in the wardrobe and the captain brandishing his twisted hook. It is hard not to see that the child has come to harm already.

The man who calls himself Sebastian follows his gaze.

“The child will come to further inconvenience. But not to harm.”

“Then where are his parents? You stole him. And here he is alone and frightened.”

“We had him stolen. But the place he comes from. . Please understand that his life was not a good one.”

“Would you have stolen him if it had been?”

“Naturally, yes. All the same, we saved him from deprivation. Though you will say that we imposed starvation on him all over again.”

There is something disarming about Sebastian. He appears to have no capacity for hiding behind self-deception. At the same time there is to him a calculation that reminds Thomas of Renfrew. He too has made a god of reason. Just now Sebastian’s mind is moving seamlessly from the ethics of child theft to the layout of London.

“Ah, I see we have passed Spitalfields Market. Time to alert the coachman to our new destination. Alas there are grave risks in leaving the city. The gates may already be watched. It may prove difficult to return.”

Sebastian is about to rap at the little window that separates them from the box, when Livia stops him. Her hands are still in her mother’s fists.

“We know a place. You won’t be found there.”

She hesitates, her eyes fierce with a kind of angry hope.

Don’t, Thomas thinks. We have no right.

But Livia does not seek his advice.