Now, so far as this went, everything fitted in finally and rationally enough. Valentin had learned by his inquiries that morning that a Father Brown from Essex was bringing up a silver cross with sapphires, a relic of considerable value, to show some of the foreign priests at the congress. This undoubtedly was the “silver with blue stones”; and Father Brown undoubtedly was the little greenhorn in the train. Now there was nothing wonderful about the fact that what Valentin had found out Flambeau had also found out; Flambeau found out everything. Also there was nothing wonderful in the fact that when Flambeau heard of a sapphire cross he should try to steal it; that was the most natural thing in all natural history. And most certainly there was nothing wonderful about the fact that Flambeau should have it all his own way with such a silly sheep as the man with the umbrella and the parcels. He was the sort of man whom anybody could lead on a string to the North Pole; it was not surprising that an actor like Flambeau, dressed as another priest, could lead him to Hampstead Heath. So far the crime seemed clear enough; and while the detective pitied the priest for his helplessness, he almost despised Flambeau for condescending to so gullible a victim. But when Valentin thought of all that had happened in between, of all that had led him to his triumph, he racked his brains for the smallest rhyme or reason in it. What had the stealing of a blue-and-silver cross from a priest from Essex to do with chucking soup at wallpaper? What had it to do with calling nuts oranges, or with paying for windows first and breaking them afterwards? He had come to the end of his chase; yet somehow he had missed the middle of it. When he failed (which was seldom), he had usually grasped the clue, but nevertheless missed the criminal. Here he had grasped the criminal, but still he could not grasp the clue.
The two figures that they followed were crawling like black flies across the huge green contour of a hill. They were evidently sunk in conversation, and perhaps did not notice where they were going; but they were certainly going to the wilder and more silent heights of the Heath. As their pursuers gained on them, the latter had to use the undignified attitudes of the deerstalker, to crouch behind clumps of trees and even to crawl prostrate in deep grass. By these ungainly ingenuities the hunters even came close enough to the quarry to hear the murmur of the discussion, but no word could be distinguished except the word “reason” recurring frequently in a high and almost childish voice. Once over an abrupt dip of land and a dense tangle of thickets, the detectives actually lost the two figures they were following. They did not find the trail again for an agonising ten minutes, and then it led round the brow of a great dome of hill overlooking an amphitheatre of rich and desolate sunset scenery. Under a tree in this commanding yet neglected spot was an old ramshackle wooden seat. On this seat sat the two priests still in serious speech together. The gorgeous green and gold still clung to the darkening horizon; but the dome above was turning slowly from peacock-green to peacock-blue, and the stars detached themselves more and more like solid jewels. Mutely motioning to his followers, Valentin contrived to creep up behind the big branching tree, and, standing there in deathly silence, heard the words of the strange priests for the first time.
After he had listened for a minute and a half, he was gripped by a devilish doubt. Perhaps he had dragged the two English policemen to the wastes of a nocturnal heath on an errand no saner than seeking figs on its thistles. For the two priests were talking exactly like priests, piously, with learning and leisure, about the most aerial enigmas of theology. The little Essex priest spoke the more simply, with his round face turned to the strengthening stars; the other talked with his head bowed, as if he were not even worthy to look at them. But no more innocently clerical conversation could have been heard in any white Italian cloister or black Spanish cathedral.
The first he heard was the tail of one of Father Brown’s sentences, which ended: “… what they really meant in the Middle Ages by the heavens being incorruptible.”
The taller priest nodded his bowed head and said:
“Ah, yes, these modern infidels appeal to their reason; but who can look at those millions of worlds and not feel that there may well be wonderful universes above us where reason is utterly unreasonable?”
“No,” said the other priest; “reason is always reasonable, even in the last limbo, in the lost borderland of things. I know that people charge the Church with lowering reason, but it is just the other way. Alone on earth, the Church makes reason really supreme. Alone on earth, the Church affirms that God himself is bound by reason.”
The other priest raised his austere face to the spangled sky and said:
“Yet who knows if in
