He turned his attention to Dalgarno, surprised how much he dreaded what he would find. And the search itself was not easy. Dalgarno was a man who seemed to do a great many things alone. It was not difficult to establish what time he had left the offices of Baltimore and Sons. A few enquiries of the desk elicited that information, but it was of little use. Dalgarno had left at six o’clock, five hours before Baltimore had been picked up by a hansom and taken to the corner of the Gray’s Inn Road.

A newsboy had seen someone who was almost certainly Dalgarno go into the Baltimore house, and half an hour later Jarvis Baltimore go in also, but he had left the street before eight, and no one that Monk could question knew anything further. The Baltimore servants would know, but he had no authority to speak to them and could think of no excuse. Even if he could have, Baltimore could have been killed at any time after midnight and before dawn. No enquiry showed one way or the other whether Dalgarno had been in his rooms all night. Exit and entry were easy, and there was no postman or other servant to see.

He spoke to the gingerbread seller on the corner fifty yards away, a small, spare man who looked as if he could profit from a thick slice of his own wares and a hot cup of tea. He had seen Dalgarno returning home at about half past nine in the evening of Baltimore’s death. Dalgarno had been walking rapidly, his face set in a mask of fury, his hat jammed hard on his head, and he had passed without a word. However, the gingerbread seller had packed up shortly after that and gone home, so he had no idea whether Dalgarno had gone out again or not.

The constable on night duty might know. He patrolled this way now and then. But he gave Monk a lopsided grin and half a wink. He did have a certain acquaintance who frequented these streets on less-open business; give him a few days and he would make enquiries.

Monk gave him half a crown, and promised him another seven to make up a sovereign, if he would do as he suggested. Only Monk would need more than a word secondhand; if there were anything, he must speak to the witness himself. What anybody else’s business was in the street would remain unknown, and unquestioned.

The constable thought for a moment or two, then agreed. Monk thanked him, said he would be back in three or four days, and took his leave.