of the tavern opened and the gigantic shadow of the investigator Flambeau fell across the table. Father Brown presented him to the lady in his own slight, persuasive style of speech, mentioning his knowledge and sympathy in such cases; and almost without knowing, the girl was soon reiterating her story to two listeners. But Flambeau, as he bowed and sat down, handed the priest a small slip of paper. Brown accepted it with some surprise and read on it: "Cab to Wagga Wagga, 379, Mafeking Avenue, Putney." The girl was going on with her story.
"I went up the steep street to my own house with my head in a whirl; it had not begun to clear when I came to the doorstep, on which I found a milk-can—and the man with the twisted nose. The milk-can told me the servants were all out; for, of course, Arthur, browsing about in his brown dressing-gown in a brown study, would not hear or answer a bell. Thus there was no one to help me in the house, except my brother, whose help must be my ruin. In desperation I thrust two shillings into the horrid thing's hand, and told him to call again in a few days, when I had thought it out. He went off sulking, but more sheepishly than I had expected—perhaps he had been shaken by his fall—and I watched the star of sand splashed on his back receding down the road with a horrid vindictive pleasure. He turned a corner some six houses down.
"Then I let myself in, made myself some tea, and tried to think it out. I sat at the drawing-room window looking on to the garden, which still glowed with the last full evening light. But I was too distracted and dreamy to look at the lawns and flower-pots and flower-beds with any concentration. So I took the shock the more sharply because I'd seen it so slowly.
"The man or monster I'd sent away was standing quite still in the middle of the garden. Oh, we've all read a lot about pale-faced phantoms in the dark; but this was more dreadful than anything of that kind could ever be. Because, though he cast a long evening shadow, he still stood in warm sunlight. And because his face was not pale, but had that waxen bloom still upon it that belongs to a barber's dummy. He stood quite still, with his face towards me; and I can't tell you how horrid he looked among the tulips and all those tall, gaudy, almost hothouse-looking flowers. It looked as if we'd stuck up a waxwork instead of a statue in the centre of our garden.
"Yet almost the instant he saw me move in the window he turned and ran out of the garden by the back gate, which stood open and by which he had undoubtedly entered. This renewed timidity on his part was so different from the impudence with which he had walked into the sea, that I felt vaguely comforted. I fancied, perhaps, that he feared confronting Arthur more than I knew. Anyhow, I settled down at last, and had a quiet dinner alone (for it was against the rules to disturb Arthur when he was rearranging the museum), and, my thoughts, a little released, fled to Philip and lost themselves, I suppose. Anyhow, I was looking blankly, but rather pleasantly than otherwise, at another window, uncurtained, but by this time black as a slate with the final night-fall. It seemed to me that something like a snail was on the outside of the window-pane. But when I stared harder, it was more like a man's thumb pressed on the pane; it had that curled look that a thumb has. With my fear and courage re-awakened together, I rushed at the window and then recoiled with a strangled scream that any man but Arthur must have heard.
"For it was not a thumb, any more than it was a snail. It was the tip of a crooked nose, crushed against the glass; it looked white with the pressure; and the staring face and eyes behind it were at first invisible and afterwards grey like a ghost. I slammed the shutters together somehow, rushed up to my room and locked myself in. But, even as I passed, I could swear I saw a second black window with something on it that was like a snail.
"It might be best to go to Arthur after all. If the thing was crawling close all around the house like a cat, it might have purposes worse even than blackmail. My brother might cast me out and curse me for ever, but he was a gentleman, and would defend me on the spot. After ten minutes' curious thinking, I went down, knocked on the door and then went in: to see the last and worst sight.
"My brother's chair was empty, and he was obviously out. But the man with the crooked nose was sitting waiting for his return, with his hat still insolently on his head, and actually reading one of my brother's books under my brother's lamp. His face was composed and occupied, but his nose-tip still had the air of being the most mobile part of his face, as if it had just turned from left to right like an elephant's proboscis. I had thought him poisonous enough while he was pursuing and watching me; but I think his unconsciousness of my presence was more frightful still.
"I think I screamed loud and long; but that doesn't matter. What I did next does matter: I gave him all the money I had, including a good deal in paper which, though it was mine, I dare say I had no right to touch. He went off at last, with hateful, tactful regrets all in long words; and I sat down, feeling ruined in every sense. And yet I was saved that very night by a pure accident. Arthur had gone off suddenly to London, as he so often did, for bargains; and returned, late but radiant, having nearly secured a treasure that was an added splendour even to the family Collection. He was so resplendent that I was almost emboldened to confess the abstraction of the lesser gem—, but he bore down all other topics with his over-powering projects. Because the bargain might still misfire any moment, he insisted on my packing at once and going up with him to lodgings he had already taken in Fulham, to be near the curio-shop in question. Thus in spite of myself, I fled from my foe almost in the dead of night—but from Philip also… . My brother was often at the South Kensington Museum, and, in order to make some sort of secondary life for myself, I paid for a few lessons at the Art Schools. I was coming back from them this evening, when I saw the abomination of desolation walking alive down the long straight street and the rest is as this gentleman has said.
"I've got only one thing to say. I don't deserve to be helped; and I don't question or complain of my punishment; it is just, it ought to have happened. But I still question, with bursting brains, how it can have happened. Am I punished by miracle? or how can anyone but Philip and myself know I gave him a tiny coin in the middle of the sea?"
"It is an extraordinary problem," admitted Flambeau.
"Not so extraordinary as the answer," remarked Father Brown rather gloomily. "Miss Carstairs, will you be at home if we call at your Fulham place in an hour and a half hence?"
The girl looked at him, and then rose and put her gloves on. "Yes," she said, "I'll be there"; and almost instantly left the place.
That night the detective and the priest were still talking of the matter as they drew near the Fulham house, a tenement strangely mean even for a temporary residence of the Carstairs family.
"Of course the superficial, on reflection," said Flambeau, "would think first of this Australian brother who's been in trouble before, who's come back so suddenly and who's just the man to have shabby confederates. But I can't see how he can come into the thing by any process of thought, unless… "
"Well?" asked his companion patiently.
Flambeau lowered his voice. "Unless the girl's lover comes in, too, and he would be the blacker villain. The Australian chap did know that Hawker wanted the coin. But I can't see how on earth he could know that Hawker had got it, unless Hawker signalled to him or his representative across the shore."
"That is true," assented the priest, with respect.
"Have you noted another thing?" went on Flambeau eagerly, "this Hawker hears his love insulted, but doesn't strike till he's got to the soft sand-hills, where he can be victor in a mere sham-fight. If he'd struck amid rocks and sea, he might have hurt his ally."
"That is true again," said Father Brown, nodding.
"And now, take it from the start. It lies between few people, but at least three. You want one person for suicide; two people for murder; but at least three people for blackmail"
"Why?" asked the priest softly.
"Well,
