There are eminent men of action who can acquit themselves with equal credit upon the little field of letters, as some of the very best books of late years go to prove. The man of letters, on the other hand, capable of cutting a respectable figure in action, is, one fears, a much rarer type. Langholm was essentially a man of letters. He was at his best among his roses and his books, at his worst in unforeseen collision with the rougher realities of life. But give him time, and he was not the man to run away because his equipment for battle was as short as his confidence in himself; and perhaps such courage as he possessed was not less courageous for the crust of cowardice (mostly moral) through which it always had to break. Langholm had one other qualification for the quest to which he had committed himself, but for which he was as thoroughly unsuited by temperament as by the whole tenor of his solitary life. In addition to an ingenious imagination (a quality with its own defects, as the sequel will show), he had that capacity for taking pains which has no disadvantageous side, though in Langholm's case, for one, it was certainly not a synonym for genius.  
It was 3.45 on the Monday afternoon when he alighted at King's Cross, having caught the 9.30 from Northborough after an early adieu to William Allen Richardson and the rest. Langholm made sure of the time before getting into his hansom at the terminus.
 
"Drive hard," he said, "to the Capital and Counties Bank in Oxford Street."
 
And he was there some minutes before the hour.
 
"I want to know my exact balance, if it is not too much trouble to look it up before you close."
 
A slip of paper was soon put into Langholm's hand, and at a glance he flushed to the hat with pleasure and surprise, and so regained his cab. "The Cadogan Hotel, in Sloane Street," he cried through the trap; "and there's no hurry, you can go your own pace."
 
Nor was there any further anxiety in Langholm's heart. His balance was a clear hundred more than he had expected to find it, and his whole soul sang the praises of a country life. Unbusinesslike and unmethodical as he was, in everything but the preparation of MS., such a discovery could never have been made in town, where Langholm's expenditure had marched arm-in-arm with his modest earnings.
 
"And it can again," he said recklessly to himself, as he decided on the best hotel in the field of his investigations, instead of lodgings; "thank God, I have enough to run this racket till the end of the year at least! If I can't strike the trail by then—"
 
He lapsed into dear reminiscence and dearer daydreams, their common scene some two hundred miles north; but to realize his lapse was to recover from it promptly. Langholm glanced at himself in the little mirror. His was an honest face, and it was an honest part that he must play, or none at all. He leaned over the apron and interested himself in the London life that was so familiar to him still. It was as though he had not been absent above a day, yet his perceptions were sharpened by his very absence of so many weeks. The wood pavement gave off a strong but not unpleasant scent in the heavy August heat; it was positively dear to the old Londoner's nostrils. The further he drove upon his southwesterly course, the emptier were the well-known thoroughfares. St. James's Street might have been closed to traffic; the clubs in Pall Mall were mostly shut. On the footways strolled the folk whom one only sees there in August and September, the entire families from the country, the less affluent American, guide book in hand. Here and there was a perennial type, the pale actor with soft hat and blue-black chin, the ragged sloucher from park to park. Langholm could have foregathered with one and all, such was the strange fascination of the town for one who was twice the man among his northern roses. But that is the kind of mistress that London is to those who have once felt her spell; you may forget her by the year, but the spell lies lurking in the first whiff of the wood pavement, the first flutter of the evening paper on the curb; and even in the cab you wonder how you have borne existence elsewhere.
 
The hotel was very empty, and Langholm found not only the best of rooms at his disposal, but that flattering quality of attention which awaits the first comer when few come at all. He refreshed himself with tea and a bath, and then set out to reconnoitre the scene of the already half-forgotten murder. He had a vague though sanguine notion that his imaginative intuition might at once perceive some possibility which had never dawned upon the academic intelligence of the police.
 
Of course he remembered the name of the street, and it was easily found. Nor had Langholm any difficulty in discovering the house, though he had forgotten the number. There were very few houses in the street, and only one of them was empty and to let. It was plastered with the bills of various agents, and Langholm noted down the neare............