nodded rather eagerly, being only too ready to explain the
Gothic splendours to someone more likely to be sympathetic than the
Presbyterian blacksmith or the atheist cobbler.

"By all means," he said; "let us go in at this side." And he led the way
into the high side entrance at the top of the flight of steps. Father
Brown was mounting the first step to follow him when he felt a hand on
his shoulder, and turned to behold the dark, thin figure of the doctor,
his face darker yet with suspicion.

"Sir," said the physician harshly, "you appear to know some secrets
in this black business. May I ask if you are going to keep them to
yourself?"

"Why, doctor," answered the priest, smiling quite pleasantly, "there is
one very good reason why a man of my trade should keep things to himself
when he is not sure of them, and that is that it is so constantly his
duty to keep them to himself when he is sure of them. But if you think
I have been discourteously reticent with you or anyone, I will go to the
extreme limit of my custom. I will give you two very large hints."

"Well, sir?" said the doctor gloomily.

"First," said Father Brown quietly, "the thing is quite in your
own province. It is a matter of physical science. The blacksmith is
mistaken, not perhaps in saying that the blow was divine, but certainly
in saying that it came by a miracle. It was no miracle, doctor, except
in so far as man is himself a miracle, with his strange and wicked and
yet half-heroic heart. The force that smashed that skull was a force
well known to scientists--one of the most frequently debated of the laws
of nature."

The doctor, who was looking at him with frowning intentness, only said:
"And the other hint?"

"The other hint is this," said the priest. "Do you remember the
blacksmith, though he believes in miracles, talking scornfully of the
impossible fairy tale that his hammer had wings and flew half a mile
across country?"

"Yes," said the doctor, "I remember that."

"Well," added Father Brown, with a broad smile, "that fairy tale was the
nearest thing to the real truth that has been said today." And with that
he turned his back and stumped up the steps after the curate.

The Reverend Wilfred, who had been waiting for him, pale and impatient,
as if this little delay were the last straw for his nerves, led him
immediately to his favourite corner of the church, that part of the
gallery closest to the carved roof and lit by the wonderful