That’s why I have had to decease.’

He had another drink, and I mixed it for him myself, for I was getting interested in the beggar.

‘They can’t get him in his own land, for he has a bodyguard of Epirotes that would skin their grandmothers. But on the 15th day of June he is coming to this city. The British Foreign Office has taken to having International tea-parties, and the biggest of them is due on that date. Now Karolides is reckoned the principal guest, and if my friends have their way he will never return to his admiring countrymen.’

‘That’s simple enough, anyhow,’ I said. ‘You can warn him and keep him at home.’

‘And play their game?’ he asked sharply. ‘If he does not come they win, for he’s the only man that can straighten out the tangle. And if his Government are warned he won’t come, for he does not know how big the stakes will be on June the 15th.’

‘What about the British Government?’ I said. ‘They’re not going to let their guests be murdered. Tip them the wink, and they’ll take extra precautions.’

‘No good. They might stuff your city with plain-clothes detectives and double the police and Constantine would still be a doomed man. My friends are not playing this game for candy. They want a big occasion for the taking off, with the eyes of all Europe on it. He’ll be murdered by an Austrian, and there’ll be plenty of evidence to show the connivance of the big folk in Vienna and Berlin. It will all be an infernal lie, of course, but the case will look black enough to the world. I’m not talking hot air, my friend. I happen to know every detail of the hellish contrivance, and I can tell you it will be the most finished piece of blackguardism since the Borgias. But it’s not going to come off if there’s a certain man who knows the wheels of the business alive right here in London on the 15th day of June. And that man is going to be your servant, Franklin P. Scudder.’

I was getting to like the little chap. His jaw had shut like a rat-trap, and there was the fire of battle in his gimlety eyes. If he was spinning me a yarn he could act up to it.

‘Where did you find out this story?’ I asked.

‘I got the first hint in an inn on the Achensee in Tyrol. That set me inquiring, and I collected my other clues in a fur-shop in the Galician quarter of Buda, in a Strangers’ Club in Vienna, and in a little bookshop off the Racknitzstrasse in Leipsic. I completed my evidence ten days ago in Paris. I can’t tell you the details now, for it’s something of a history. When I was quite sure in my own mind I judged it my business to disappear, and I reached this city by a mighty queer circuit. I left Paris a dandified young French-American, and I sailed from Hamburg a Jew diamond merchant. In Norway I was an English student of Ibsen collecting materials for lectures, but when I left Bergen I was a cinema-man with special ski films. And I came here from Leith with a lot of pulp-wood propositions in my pocket to put before the London newspapers. Till yesterday I thought I had muddied my trail some, and was feeling pretty happy. Then ...’

The recollection seemed to upset him, and he gulped down some more whisky.

‘Then I saw a man standing in the street outside this block.