Dashing down to the front hall he then laid
similar charges of vigilance on the commissionaire at the front door,
from whom he learned the simplifying circumstances that there was no
back door. Not content with this, he captured the floating policeman
and induced him to stand opposite the entrance and watch it; and finally
paused an instant for a pennyworth of chestnuts, and an inquiry as to
the probable length of the merchant's stay in the neighbourhood.

The chestnut seller, turning up the collar of his coat, told him he
should probably be moving shortly, as he thought it was going to snow.
Indeed, the evening was growing grey and bitter, but Angus, with all his
eloquence, proceeded to nail the chestnut man to his post.

"Keep yourself warm on your own chestnuts," he said earnestly. "Eat
up your whole stock; I'll make it worth your while. I'll give you a
sovereign if you'll wait here till I come back, and then tell me
whether any man, woman, or child has gone into that house where the
commissionaire is standing."

He then walked away smartly, with a last look at the besieged tower.

"I've made a ring round that room, anyhow," he said. "They can't all
four of them be Mr. Welkin's accomplices."

Lucknow Mansions were, so to speak, on a lower platform of that hill
of houses, of which Himylaya Mansions might be called the peak. Mr.
Flambeau's semi-official flat was on the ground floor, and presented
in every way a marked contrast to the American machinery and cold
hotel-like luxury of the flat of the Silent Service. Flambeau, who was
a friend of Angus, received him in a rococo artistic den behind his
office, of which the ornaments were sabres, harquebuses, Eastern
curiosities, flasks of Italian wine, savage cooking-pots, a plumy
Persian cat, and a small dusty-looking Roman Catholic priest, who looked
particularly out of place.

"This is my friend Father Brown," said Flambeau. "I've often wanted you
to meet him. Splendid weather, this; a little cold for Southerners like
me."

"Yes, I think it will keep clear," said Angus, sitting down on a
violet-striped Eastern ottoman.

"No," said the priest quietly, "it has begun to snow."

And, indeed, as he spoke, the first few flakes, foreseen by the man of
chestnuts, began to drift across the darkening windowpane.

"Well," said Angus heavily. "I'm afraid I've come on business, and
rather jumpy business at that. The fact is, Flambeau, within a stone's
throw of your house