"There are five colossal difficulties,"said the doctor quietly,"like high walls within walls. Don't mistake me.I don't doubt that Brayne did it;his flight, I fancy, proves that.But as to how he did it.First difficulty:Why should a man kill another man with a great hulking sabre, when he can almost kill him with a pocket knife and put it back in his pocket?Second difficulty:Why was there no noise or outcry?Does a man commonly see another come up waving a scimitar and offer no remarks?Third difficulty:A servant watched the front door all the evening;and a rat cannot get into Valentin's garden anywhere.How did the dead man get into the garden?Fourth difficulty:Given the same conditions, how did Brayne get out of the garden?"
"And the fifth."said Neil, with eyes fixed on the English priest who was coming slowly up the path.
"Is a trifle, I suppose,"said the doctor,"but I think an odd one. When I first saw how the head had been slashed, I supposed the assassin had struck more than once.But on examination I found many cuts across the truncated section;in other words, they were struck after the head was off.Did Brayne hate his foe so fiendishly that he stood sabring his body in the moonlight?"
"Horrible!"said O'Brien, and shuddered.
The little priest, Brown, had arrived while they were talking, and had waited, with characteristic shyness, till they had finished. Then he said awkwardly:
"I say, I'm sorry to interrupt. But I was sent to tell you the news!"
"News?"repeated Simon, and stared at him rather painfully through his glasses.
"Yes, I'm sorry,"said Father Brown mildly."There's been another murder, you know."
Both men on the seat sprang up, leaving it rocking.
"And, what's stranger still,"continued the priest, with his dull eye on the rhododendrons,"it's the same disgusting sort;it's another beheading. They found the second head actually bleeding into the river, a few yards along Brayne's road to Paris;so they suppose that he-"