Wilfred’s face was turned away, but his bony hands turned blue and white as they tightened on the parapet of stone.

“He thought it was given to him to judge the world and strike down the sinner.  He would never have had such a thought if he had been kneeling with other men upon a floor.  But he saw all men walking about like insects.  He saw one especially strutting just below him, insolent and evident by a bright green hat—­a poisonous insect.”

Rooks cawed round the corners of the belfry; but there was no other sound till Father Brown went on.

“This also tempted him, that he had in his hand one of the most awful engines of nature; I mean gravitation, that mad and quickening rush by which all earth’s creatures fly back to her heart when released.  See, the inspector is strutting just below us in the smithy.  If I were to toss a pebble over this parapet it would be something like a bullet by the time it struck him.  If I were to drop a hammer—­even a small hammer—­”

Wilfred Bohun threw one leg over the parapet, and Father Brown had him in a minute by the collar.

“Not by that door,” he said quite gently; “that door leads to hell.”

Bohun staggered back against the wall, and stared at him with frightful eyes.

“How do you know all this?” he cried.  “Are you a devil?”

“I am a man,” answered Father Brown gravely; “and therefore have all devils in my heart.  Listen to me,” he said after a short pause.  “I know what you did—­at least, I can guess the great part of it.  When you left your brother you were racked with no unrighteous rage, to the extent even that you snatched up a small hammer, half inclined to kill him with his foulness on his mouth.  Recoiling, you thrust it under your buttoned coat instead, and rushed into the church.  You pray wildly in many places, under the angel window, upon the platform above, and a higher platform still, from which you could see the colonel’s Eastern hat like the back of a green beetle crawling about.  Then something snapped in your soul, and you let God’s thunderbolt fall.”

Wilfred put a weak hand to his head, and asked in a low voice:  “How did you know that his hat looked like a green beetle?”

“Oh, that,” said the other with the shadow of a smile, “that was common sense.  But hear me further.  I say I know all this; but no one else shall know it.  The next step is for you; I shall take no more steps; I will seal this with the seal of confession.  If you ask me why, there are many reasons, and only one that concerns you.  I leave things to you because you have not yet gone very far wrong, as assassins go.  You did not help to fix the crime on the smith when it was easy; or on his wife, when that was easy.  You tried to fix it on the imbecile because you knew that he could not suffer.  That was one of the gleams that it is my business to find in assassins.  And now come down into the village, and go your own way as free as the wind; for I have said my last word.”