London was silent with snow; soft flakes of it dropping evenly into the white streets; nobody outside who had somewhere inside to be. It was the third day of the year. Already the light was fading, though it was scarcely past two o'clock in the afternoon, and in his study in Mayfair, Charles Lenox allowed his watchful eyes to rest upon the large set of windows at the opposite end of the room, the long room, far from the dying fire by which he sat.

He was alone in the house but for servants. His wife, Jane, and their four-year-old daughter, Sophia, were still at her brother's house in the country, but business, on behalf of the detective agency of which he numbered one of the three partners, had drawn him back to London earlier than he had anticipated.

But not enough business, alas, to keep him occupied for more than a few hours the previous afternoon, so that on this lonely and endless Sunday he had already reorganized the long rows of books that lined the walls, had gone through several pots of tea — and above all had waited, waited, waited, all the infinite day through, for a certain visitor to come.

And still no sign of him.

Lenox hadn't looked at the letter heralding this visit since late that morning, but he was conscious at every moment of just where it sat on his desk in its long, crisp envelope, its cryptic contents never far from his thoughts. Out of sheer nervous energy he wanted to open it again. But if he closed his eyes he could probably recite it.

It was on the stationery of the hotel from which it was addressed.

The Collingwood 3rd January 1877

Lenox,

I am writing in some haste — too much haste, certainly, to set down the reflections I wish I could of our distant friendship. As you can see, I am in London at the moment. Only briefly, however. Your address (I hope it may still be the correct one) was in the school directory.

It comes to this: I am in trouble. And yet I am not even quite sure how I am in trouble. I think it may be connected to that business that you and I once

Here the letter broke off abruptly.

It began again after some space on the page, with the darkness at the outset of this new passage making it clear that its author had taken a fresh nibful of ink — had resumed his communication after being momentarily drawn away from it.

I must go. No time to explain further. Send word by return post and I will call upon you there in Hampden Lane, most likely after three o'clock.

Even in such circumstances I will be pleased to meet again. Until then believe me to be, in sincerest regards and fondest remembrances, your friend,

Gerald R. Leigh

The carriage clock on Lenox's desk had just swung its small bells to tap each other together once, which meant it was two forty-five. Sitting motionless in his armchair, after his restless day, he felt an irrepressible urge to do something — to act. But there was nothing to do, and no act to perform. He had forbidden himself another examination of the letter.

Which of course meant that at 2:48 he found himself, not quite consciously, standing up out of his chair and striding across the room to examine it again.

The hotel's stationery revealed precious little. Lenox was forty-seven now — a tall and thin man, with a close brown beard and a thoughtful, kindly, but undeceived face — and had been a detective since roughly the age of twenty-two, first as a private investigator, now as a professional in the agency he had founded with two close friends. (For several years between these stages of his career, he had been in Parliament, the ancient family game, but that was in the past now.)

Across that long period, one of the few things he had very definitely learned was how to look at a letter. Some of the most innocuous among them had also been the most decisive — in an early case, he recalled, the Hoxley silver thief had been sent away for life on the strength of a note to his partner that said "A bit peckish" — but this one stubbornly refused to reveal anything to him.

The Collingwood was a first-rate hotel. That was just faintly surprising, perhaps, since Leigh was an unpretentious soul.

His handwriting here had a ghost of familiarity to it, long-ago familiarity, dormant now for nearly thirty years. (Gerald Leigh, no less! Well, he could marvel at this reappearance at his leisure. For now he must concentrate.) There was one obviously notable thing here, the letter's sudden interruption and its reference to Leigh's trouble. And one more subtly interesting clue: He had sealed the envelope with a signet ring, and Lenox could just make out that its looping intertwined initials were not Leigh's own.

RSR, he thought. Or perhaps, upon closer scrutiny, BSB. Maddening, the artistic freedom these jewelers felt it within their rights to take with the alphabet.

Lenox stood up from his bent position, tapping the envelope thoughtfully against the desk, a hand thrust in the pocket what his wife had named his study-jacket. Brushing its torn lining with his fingers he felt, just somewhere in the back of his consciousness, a pang of anxiety about Lady Jane, and a puzzlement, too.

Study-jacket, that was her all over — a denomination designed to remind him, not especially gently, that it was a garment unwelcome in any other room of the house, the jacket being a deeply injured old quilted blue smoker, covered with burn marks and the stains of innumerable spills from coffee and teacups, its wrists singed and smudged.

But she also knew it was the jacket he thought best in — he didn't care if that was silly; a detective needed superstitions — and as a consequence made certain, in her loving way, that it was always on its hook, brushed as clean as it could get in these latter stages of its life, and with a charcoal pencil in the pocket in case Lenox needed to jot something down.

He hoped they were all right, he and Jane. They had to be, of course.

The hands of the little clock on the desk ached forward. Two fifty-four, two fifty-five. Outside, the snow fell. The little bookshop across the way had a drowsy low fire in its window, and Lenox knew that its proprietor, a friend of long standing, would be sound asleep in his armchair with a book open across his belly. The image made him consider what could have brought Leigh to London, and what problem (or what "trouble," to use his word) could have driven him out of doors on a day such as this one.

That business that you and I once.

This was the sentence that had kept its hooks in Lenox throughout the day. For he knew full well, or thought he did, to what it referred: his very first case as a detective, in a way.

The clock took Lenox past the hour and he went to sit in the cushioned window seat that looked across Hampden Lane. The panes were very cold to the touch; the snow was relentless, reckless with the plans that Londoners had made.

Three-fifteen and the bells touched once; three-thirty and they did it again, twice now.

At four, Lenox began to worry.

It was at five o'clock, having spent the hour in no more fruitful activity than willing it to pass, and, now that it had, having nothing to show for it, that he cried out "Kirk!" in a loud, irritated voice.

After a long beat the house's phlegmatic, pear-shaped butler appeared. "Sir?"

"You can tell...