“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.”