"No," said Father Brown simply, and stood up also, "you won't take it by force. First, because I really haven't still got it. And, second, because we are not alone."

Flambeau stopped in his stride forward.

"Behind that tree," said Father Brown, pointing, "are two strong policemen and the greatest detective alive. How did they come here, do you ask? Why, I brought them, of course! How did I do it? Why, I'll tell you if you like! Lord bless you, we have to know twenty such things when we work among the criminal classes! Well, I wasn't sure you were a thief, and it would never do to make a scandal against one of our own clergy. So I just tested you to see if anything would make you show yourself. A man generally makes a small scene if he finds salt in his coffee; if he doesn't, he has some reason for keeping quiet. I changed the salt and sugar, and you kept quiet. A man generally objects if his bill is three times too big. If he pays it, he has some motive for passing unnoticed. I altered your bill, and you paid it."

The world seemed waiting for Flambeau to leap like a tiger. But he was held back as by a spell; he was stunned with the utmost curiosity.

"Well," went on Father Brown, with lumbering lucidity, "as you wouldn't leave any tracks for the police, of course somebody had to. At every place we went to, I took care to do something that would get us talked about for the rest of the day. I didn't do much harm—a splashed wall, spilt apples, a broken window; but I saved the cross, as the cross will always be saved. It is at Westminster by now. I rather wonder you didn't stop it with the Donkey's Whistle."

"With the what?" asked Flambeau.

"I'm glad you've never heard of it," said the priest, making a face. "It's a foul thing. I'm sure you're too good a man for a Whistler. I couldn't have countered it even with the Spots myself; I'm not strong enough in the legs."

"What on earth are you talking about?" asked the other.

"Well, I did think you'd know the Spots," said Father Brown, agreeably surprised. "Oh, you can't have gone so very wrong yet!"

"How in blazes do you know all these horrors?" cried Flambeau.

The shadow of a smile crossed the round, simple face of his clerical opponent.

"Oh, by being a celibate simpleton, I suppose," he said. "Has it never struck you that a man who does next to nothing but hear men's real sins is not likely to be wholly unaware of human evil? But, as a matter of fact, another part of my trade, too, made me sure you weren't a priest."

"What?" asked the thief, almost gaping.

"You attacked reason," said Father Brown. "It's bad theology."

And even as he turned away to collect his property, the three policemen came out from under the twilight trees. Flambeau was an artist and a sportsman. He stepped back and swept Valentin a great bow.

"Do not bow to me, mon ami," said Valentin with silver clearness. "Let us both bow to our master."

And they both stood an instant uncovered while the little Essex priest blinked about for his umbrella.

Aristide Valentin, Chief of the Paris Police, was late for his dinner, and some of his guests began to arrive before him. These were, however, reassured by his confidential servant, Ivan, the old man with a scar, and a face almost as grey as his moustaches, who always sat at a table in the entrance hall—a hall hung with weapons. Valentin's house was perhaps as peculiar and celebrated as its master. It was an old house, with high walls and tall poplars almost overhanging the Seine; but the oddity—and perhaps the police value—of its architecture was this: that there was no ultimate exit at all except through this front door, which was guarded by Ivan and the armoury. The garden was large and elaborate, and there were many exits from the house into the garden. But there was no exit from the garden into the world outside; all round it ran a tall, smooth, unscalable wall with special spikes at the top; no bad garden, perhaps, for a man to reflect in whom some hundred criminals had sworn to kill.

As Ivan explained to the guests, their host had telephoned that he was detained for ten minutes. He was, in truth, making some last arrangements about executions and such ugly things; and though these duties were rootedly repulsive to him, he always performed them with precision. Ruthless in the pursuit of criminals, he was very mild about their punishment. Since he had been supreme over French—and largely over European—policial methods, his great influence had been honourably used for the mitigation of sentences and the purification of prisons. He was one of the great humanitarian French freethinkers; and the only thing wrong with them is that they make mercy even colder than justice.

When Valentin arrived he was already dressed in black clothes and the red rosette—an elegant figure, his dark beard already streaked with grey. He went straight through his house to his study, which opened on the grounds behind. The garden door of it was open, and after he had carefully locked his box in its official place, he stood for a few seconds at the open door looking out upon the garden. A sharp moon was fighting with the flying rags and tatters of a storm, and Valentin regarded it with a wistfulness unusual in such scientific natures as his. Perhaps such scientific natures have some psychic prevision of the most tremendous problem of their lives. From any such occult mood, at least, he quickly recovered, for he knew he was late, and that his guests had already begun to arrive. A glance at his drawing-room when he entered it was enough to make certain that his principal guest was not there, at any rate. He saw all the other pillars of the little party; he saw Lord Galloway, the English Ambassador—a choleric old man with a russet face like an apple, wearing the blue ribbon of the Garter. He saw Lady Galloway, slim and threadlike, with silver hair and a face sensitive and superior. He saw her daughter, Lady Margaret Graham, a pale and pretty girl with an elfish face and copper-coloured hair. He saw the Duchess of Mont St. Michel, black-eyed and opulent, and with her her two daughters, black-eyed and opulent also. He saw Dr. Simon, a typical French scientist, with glasses, a pointed brown beard, and a forehead barred with those parallel wrinkles which are the penalty of superciliousness, since they come through constantly elevating the eyebrows. He saw Father Brown, of Cobhole, in Essex, whom he had recently met in England. He saw—perhaps with more interest than any of these—a tall man in uniform, who had bowed to the Galloways without receiving any very hearty acknowledgment, and who now advanced alone to pay his respects to his host. This was Commandant O'Brien, of the French Foreign Legion. He was a slim yet somewhat swaggering figure, clean-shaven, dark-haired, and blue-eyed, and, as seemed natural in an officer of that famous regiment of victorious failures and successful suicides, he had an air at once dashing and melancholy. He was by birth an Irish gentleman, and in boyhood had known the Galloways—especially Margaret Graham. He had left his country after some crash of debts, and now expressed his complete freedom from British etiquette by swinging about in uniform, sabre and spurs. When he bowed to the Ambassador's family, Lord and Lady Galloway bent stiffly, and Lady Margaret looked away.

But for whatever old causes such people might be interested in each other, their distinguished host was not specially interested in them. No one of them at least was in his eyes the guest of the evening. Valentin was expecting, for special reasons, a man of world-wide fame, whose friendship he had secured during some of his great detective tours and triumphs in the United States. He was expecting Julius K. Brayne, that multi-millionaire whose colossal and even crushing endowments of small religions have occasioned so much easy sport and easier solemnity for the American and English papers. Nobody could quite make out whether Mr. Brayne was an atheist or a Mormon or a Christian Scientist; but he was ready to pour money into any intellectual vessel, so long as it was an untried vessel. One of his hobbies was to wait for the American Shakespeare—a hobby more patient than angling. He admired Walt Whitman, but thought that Luke P. Tanner, of Paris, Pa., was more "progressive" than Whitman any day. He liked anything that he thought "progressive." He thought Valentin "progressive," thereby doing him a grave injustice.