"Happy to see you, gentlemen; pray come in."Out of a hole in an enormous dark egg-shaped thing, pendent in the branches like a wasps' nest, was protruding the pale face and fierce moustache of the lieutenant, his teeth shining with that slightly Southern air that belonged to him.

Somehow or other, stunned and speechless, we lifted ourselves heavily into the opening.We fell into the full glow of a lamp-lit, cushioned, tiny room, with a circular wall lined with books, a circular table, and a circular seat around it.At this table sat three people.One was Basil, who, in the instant after alighting there, had fallen into an attitude of marmoreal ease as if he had been there from boyhood; he was smoking a cigar with a slow pleasure.The second was Lieutenant Drummond Keith, who looked happy also, but feverish and doubtful compared with his granite guest.The third was the little bald-headed house-agent with the wild whiskers, who called himself Montmorency.The spears, the green umbrella, and the cavalry sword hung in parallels on the wall.The sealed jar of strange wine was on the mantelpiece, the enormous rifle in the corner.In the middle of the table was a magnum of champagne.Glasses were already set for us.

The wind of the night roared far below us, like an ocean at the foot of a light-house.The room stirred slightly, as a cabin might in a mild sea.

Our glasses were filled, and we still sat there dazed and dumb.

Then Basil spoke.

"You seem still a little doubtful, Rupert.Surely there is no further question about the cold veracity of our injured host.""I don't quite grasp it all," said Rupert, blinking still in the sudden glare."Lieutenant Keith said his address was--""It's really quite right, sir," said Keith, with an open smile.

"The bobby asked me where I lived.And I said, quite truthfully, that I lived in the elms on Buxton Common, near Purley.So I do.

This gentleman, Mr Montmorency, whom I think you have met before, is an agent for houses of this kind.He has a special line in arboreal villas.It's being kept rather quiet at present, because the people who want these houses don't want them to get too common.

But it's just the sort of thing a fellow like myself, racketing about in all sorts of queer corners of London, naturally knocks up against.""Are you really an agent for arboreal villas?" asked Rupert eagerly, recovering his ease with the romance of reality.

Mr Montmorency, in his embarrassment, fingered one of his pockets and nervously pulled out a snake, which crawled about the table.

"W-well, yes, sir," he said."The fact was--er--my people wanted me very much to go into the house-agency business.But I never cared myself for anything but natural history and botany and things like that.My poor parents have been dead some years now, but--naturally I like to respect their wishes.And I thought somehow that an arboreal villa agency was a sort of--of compromise between being a botanist and being a house-agent."Rupert could not help laughing."Do you have much custom?" he asked.

"N-not much," replied Mr Montmorency, and then he glanced at Keith, who was (I am convinced) his only client."But what there is--very select.""My dear friends," said Basil, puffing his cigar, "always remember two facts.The first is that though when you are guessing about any one who is sane, the sanest thing is the most likely; when you are guessing about any one who is, like our host, insane, the maddest thing is the most likely.The second is to remember that very plain literal fact always seems fantastic.If Keith had taken a little brick box of a house in Clapham with nothing but railings in front of it and had written `The Elms' over it, you wouldn't have thought there was anything fantastic about that.Simply because it was a great blaring, swaggering lie you would have believed it.""Drink your wine, gentlemen," said Keith, laughing, "for this confounded wind will upset it."We drank, and as we did so, although the hanging house, by a cunning mechanism, swung only slightly, we knew that the great head of the elm tree swayed in the sky like a stricken thistle.