In the next picture in the sequence, a tent city had sprung up in front of the elaborate Victorian houses that faced the park. Here, the rising smoke was closer, possessions had been gathered into rough heaps, and a few canvas tents had been raised, the whiteness of their sides and the unbeaten grass around their bases clear signs that the photograph had been taken soon after they had been installed. The women were mostly bare-headed, and the men had returned, to stand about in their shirt-sleeves.

“The Army brought the tents over,” Miss Adderley said, “I believe from Fort Mason. At first there were soldiers to set them up, but then they were called off to guard the downtown from looters and we were left to our own resources. Fortunately, a number of old soldiers lived in the area, so we managed. This was our tent, here.” A gnarled finger touched a taut white peak near the house at the top of the hill, then continued down to the bottom to turn to the next page.

Now, the Lafayette Park tent city was well established, peopled by an affluent group of refugees, long-skirted women with the occasional hat, their prized bits of furniture and statuary bulging the sides of the tents—a sofa here, two candelabra on a packing-case table there. All the children wore shoes, and the men, though still not as numerous as the women, invariably wore waistcoats and bowler hats.

As the days went on, the tents began to sag, more men appeared, the children started to look more unkempt, and the women took on harried expressions. The grass turned to mud; sloppy tarpaulins draped possessions.

Then, five pages in, the small hand splayed across the page and Miss Adderley leant forward with a noise of satisfaction.

“Yes, I thought so. You see the figure in trousers there? If you look closely, you'll see it's a woman. That was Mrs Russell.” Holmes already had his magnifying-glass from his pocket and was bending over the page. “That lamp on the other end of the settee is quite bright, if you like,” she suggested.

He carried the album over to the lamp, resting the top edge of the book against the arm of the settee. He switched on the lamp, brought his glass into play, and Judith Russell looked back at him from over the years.

Her daughter's hair, eyes, and height all came from the father's side, but the tilt of the chin was instantly recognisable, and the tug of amusement at the corner of the mouth was exactly as Holmes had seen it a thousand times.

For the first time, Holmes felt a stab of regret, as a personal element entered the case: His wife's mother was a person he'd like to have met.

He shook off the distracting thought, and shifted the glass to one side.