And if Monk had betrayed Arrol Dundas, and had even the slightest knowing or willing hand in the rail crash in the past, then he had never been the man Hester believed him to be, and everything he had so carefully built, with such difficult letting go of his pride, would come shattering down like a house of cards.

Suddenly this woman he barely knew was closer to him than anyone else, because they shared a fear which dominated their lives to the exclusion of everything else.

She was still staring at him in terrified silence.

“Miss Harcus,” he said with a tenderness that startled him, and this time he did not hesitate to touch her. It was only a small gesture, but of extraordinary understanding. “I will find out the truth,” he promised. “If there is a fraud, I’ll uncover it and prevent any further accidents. And I will do what I can to discover who murdered Nolan Baltimore.” He watched her gravely. “But unless there is fraud, and Michael Dalgarno is implicated, he would have no motive to have done such a thing. Baltimore was probably killed in some fight over money to do with prostitution, not a fortune but a few pounds some drunken pimp thought he owed. They may well have had no idea who he was. Had he a hot temper?”

The faintest shadow of a smile touched her lips, and her whole body eased its stiffness. “Yes,” she whispered. “Yes, he was quick-tempered. Thank you more than I can say, Mr. Monk. You have at least given me hope. I shall cling onto that until you bring me news.” Her eyes flickered down, then up again. “I must owe you further, and you have expenses from all the traveling you have done on my behalf. Would another fifteen pounds be sufficient for the moment? It . . . it is all I can manage.” There was a faint flush of embarrassment on her cheeks now.

“It would be quite sufficient,” he answered, taking it from her hand and putting it into his inside pocket as discreetly as possible, pulling out a handkerchief as if that were what he had reached for. He saw her flash of understanding and acknowledgment and was sufficiently thanked in that.

It was time that Monk considered more seriously the possibility that Baltimore’s death was not the prostitution scandal that the police, and everyone else, assumed, but a very personal murder simply carried out in or near the brothel in Leather Lane. If Dalgarno, or even Jarvis Baltimore, had wished to kill the older man, to do it behind the mask of his private vices was the perfect crime.