Horses were intelligent animals, and very much creatures of habit. If Treadwell had driven them to Hampstead before then, they were likely to have returned to the same place.

Accordingly, the still, summer morning at seven o’clock found Monk standing in the sun on Lyndhurst Road, studying its tidy house fronts with their neat gardens and whitened steps.

He knew Miriam’s address from Lucius Stourbridge. Naturally, it was the first place he had enquired, but all his questions had elicited only blank ignorance and then growing alarm. That might still be where Robb would begin.

Monk stood with the lazy sun warming his shoulders and the early-morning sounds of kitchen doors opening and closing, the occasional whack of a broom handle beating a carpet. Errand boys’ feet were loud on the cobbles, as was the uneven step of one of them who was carrying a heavy bucket of coal. The only thought crowding his mind was where had Miriam been when James Treadwell was murdered. Had she been present? If she had, had anyone else, or had she killed him herself? The surgeon had said it seemed a single, extremely heavy blow, but not impossible to have been inflicted by a woman, given that she had used the right weapon. And Treadwell had not died straightaway but crawled from wherever it had happened, presumably looking for help. Neither Robb nor the police surgeon had offered any suggestion as to where the crime had taken place, but it could not have been far away.

Had Miriam struck him once and then fled? Had she taken the coach, driving it herself? If so, why had she abandoned it in the street so close by?

Perhaps she had panicked and simply run, as the blind, instinctive thing to do. Possibly she was unused to horses and did not know how to drive.

Or had there been a third person there? Had Miriam witnessed the murder and fled, perhaps for her own survival? Or had she not been there at all?

He would learn nothing standing in the sun while the world woke up and busied itself around him. He walked forward and up the step to the nearest door. He knocked on it and the maid answered, looking startled and ready to tell any errant tradesman where his appropriate entrance was and not to be so impertinent as to come to the front. Then she saw Monk’s face, and her eyes traveled down his smart coat to his polished boots, and she changed her mind.

"Yes sir?" she said curiously, absentmindedly pushing her hand through her hair to tidy it out of her eyes. "Master’s not up yet, I’m afraid." Then she realized that was a little too revealing. "I mean, ’e in’t ’ad ’is breakfast yet."

Monk made himself smile at the girl. "I’m sure you can help me without disturbing the household. I’m afraid I am lost. I don’t know the area very well. I am looking for a Mrs. Miriam Gardiner. I believe she lives somewhere near here." He knew perfectly well that she lived about five houses along, but he wanted to learn all he could from someone who almost certainly would have noticed her and heard all the below-stairs gossip. If indeed there had been some relationship between her and Treadwell, then they might have been less guarded here, away from Cleveland Square.