was long, low, and dark; what light entered it shot from under low blinds and had still some of the ruddy tinge of morning. Valentin and his servant Ivan were waiting for them at the upper end of a long, slightly-sloping desk, on which lay the mortal remains, looking enormous in the twilight. The big black figure and yellow face of the man found in the garden confronted them essentially unchanged. The second head, which had been fished from among the river reeds that morning, lay streaming and dripping beside it; Valentin's men were still seeking to recover the rest of this second corpse, which was supposed to be afloat. Father Brown, who did not seem to share O'Brien's sensibilities in the least, went up to the second head and examined it with his blinking care. It was little more than a mop of wet white hair, fringed with silver fire in the red and level morning light; the face, which seemed of an ugly, empurpled and perhaps criminal type, had been much battered against trees or stones as it tossed in the water.
"Good morning, Commandant O'Brien," said Valentin, with quiet cordiality. "You have heard of Brayne's last experiment in butchery, I suppose?"
Father Brown was still bending over the head with white hair, and he said, without looking up:
"I suppose it is quite certain that Brayne cut off this head, too."
"Well, it seems common sense," said Valentin, with his hands in his pockets. "Killed in the same way as the other. Found within a few yards of the other. And sliced by the same weapon which we know he carried away."
"Yes, yes; I know," replied Father Brown submissively. "Yet, you know, I doubt whether Brayne could have cut off this head."
"Why not?" inquired Dr. Simon, with a rational stare.
"Well, doctor," said the priest, looking up blinking, "can a man cut off his own head? I don't know."
O'Brien felt an insane universe crashing about his ears; but the doctor sprang forward with impetuous practicality and pushed back the wet white hair.
"Oh, there's no doubt it's Brayne," said the priest quietly. "He had exactly that chip in the left ear."
The detective, who had been regarding the priest with steady and glittering eyes, opened his clenched mouth and said sharply: "You seem to know a lot about him, Father Brown."
"I do," said the little man simply. "I've been about with him for some weeks. He was thinking of joining our church."
The star of the fanatic sprang into Valentin's eyes; he strode towards the priest with clenched hands. "And, perhaps," he cried, with a blasting sneer, "perhaps he was also thinking of leaving all his money to your church."
"Perhaps he was," said Brown stolidly; "it is possible."
"In that case," cried Valentin, with a dreadful smile, "you may indeed know a great deal about him. About his life and about his——"
Commandant O'Brien laid a hand on Valentin's arm. "Drop that slanderous rubbish, Valentin," he said, "or there may be more swords yet."
But Valentin (under the steady, humble gaze of the priest) had already recovered himself. "Well," he said shortly, "people's private opinions can wait. You gentlemen are still bound by your promise to stay; you must enforce it on yourselves—and on each other. Ivan here will tell you anything more you want to know; I must get to business and write to the authorities. We can't keep this quiet any longer. I shall be writing in my study if there is any more news."
"Is there any more news, Ivan?" asked Dr. Simon, as the chief of police strode out of the room.
"Only one more thing, I think, sir," said Ivan, wrinkling up his grey old face, "but that's important, too, in its way. There's that old buffer you found on the lawn," and he pointed without pretence of reverence at the big black body with the yellow head. "We've found out who he is, anyhow."
"Indeed!" cried the astonished doctor, "and who is he?"
"His name was Arnold Becker," said the under-detective, "though he went by many aliases. He was a wandering sort of scamp, and is known to have been in America; so that was where Brayne got his knife into him. We didn't have much to do with him ourselves, for he worked mostly in Germany. We've communicated, of course, with the German police. But, oddly enough, there was a twin brother of his, named Louis Becker, whom we had a great deal to do with. In fact, we found it necessary to guillotine him only yesterday. Well, it's a rum thing, gentlemen, but when I saw that fellow flat on the lawn I had the greatest jump of my life. If I hadn't seen Louis Becker guillotined with my own eyes, I'd have sworn it was Louis Becker lying there in the grass. Then, of course, I remembered his twin brother in Germany, and following up the clue——"
The explanatory Ivan stopped, for the excellent reason that nobody was listening to him. The Commandant and the doctor were both staring at Father Brown, who had sprung stiffly to his feet, and was holding his temples tight like a man in sudden and violent pain.
"Stop, stop, stop!" he cried; "stop talking a minute, for I see half. Will God give me strength? Will my brain make the one jump and see all? Heaven help me! I used to be fairly good at thinking. I could paraphrase any page in Aquinas once. Will my head split—or will it see? I see half—I only see half."
He buried his head in his hands, and stood in a sort of rigid torture of thought or prayer, while the other three could only go on staring at this last prodigy of their wild twelve hours.
When Father Brown's hands fell they showed a face quite fresh and serious, like a child's. He heaved a huge sigh, and said: "Let us get this said and done with as quickly as possible. Look here, this will be the quickest way to convince you all of the truth." He turned to the doctor. "Dr. Simon," he said, "you have a strong head-piece, and I heard you this morning asking the five hardest questions about this business. Well, if you will ask them again, I will answer them."
Simon's pince-nez dropped from his nose in his doubt and wonder, but he answered at once. "Well, the first question, you know, is why a man should kill another with a clumsy sabre at all when a man can kill with a bodkin?"
"A man cannot behead with a bodkin," said Brown calmly, "and for this murder beheading was absolutely necessary."
"Why?" asked O'Brien, with interest.
"And the next question?" asked Father Brown.
"Well, why didn't the man cry out or anything?" asked the doctor; "sabres in gardens are certainly unusual."
"Twigs," said the priest gloomily, and turned to the window which looked on the scene of death. "No one saw the point of the twigs. Why should they lie on that lawn (look at it) so far from any tree? They were not snapped off; they were chopped off. The murderer occupied his enemy with some tricks with the sabre, showing how he could cut a branch in mid-air, or whatnot. Then, while his enemy bent down to see the result, a silent slash, and the head fell."
"Well," said the doctor slowly, "that seems plausible enough. But my next two questions will stump anyone."
The priest still stood looking critically out of the window and waited.
"You know how all the garden was sealed up like an air-tight chamber," went on the doctor. "Well, how did the strange man get into the garden?"
Without turning round, the little priest answered: "There never was any strange man in the garden."
There was a silence, and then a sudden cackle of almost childish laughter relieved the strain. The absurdity of Brown's remark moved Ivan to open taunts.
