“Well,” I observed thoughtfully, “Clubfoot, whoever he is, seems to have made every effort to keep my escapades dark....”

“Precisely,” said Francis, “and lucky for you too.  Otherwise Clubfoot would have had you stopped at the frontier.  But obviously secrecy is an essential part of his instructions, and he has shown himself willing to risk almost anything rather than call in the aid of the regular police.”

“But they can always hush these things up!” I objected.

“From the public, yes, but not from the Court.  This letter looks uncommonly like one of William’s sudden impulses ... and I fancy anything of the kind would get very little tolerance in Germany in war-time.”

“But who is Clubfoot?” I questioned.

My brother furrowed his brows anxiously.

“Des,” he said, “I don’t know.  He is certainly not a regular official of the German Intelligence like Steinhauer and the others.  But I have heard of a clubfooted German on two occasions ... both were dark and mysterious affairs, in both he played a leading role and both ended in the violent death of one of our men.”

“Then Tracy and the others...?” I asked.

“Victims of this man, Des, without any doubt,” my brother answered.  He paused a moment reflectively.

“There is a code of honour in our game, old man,” he said, “and there are lots of men in the German secret service who live up to it.  We give and take plenty of hard knocks in the rough-and-tumble of the chase, but ambush and assassination are barred.”

He took a deep breath and added: 

“But the man Clubfoot doesn’t play the game!”

“Francis,” I said, “I wish I’d known something of this that night I had him at my mercy at the Esplanade.  He would not have got off with a cracked skull ... with one blow.  There would have been another blow for Tracy, one for Arbuthnot, one for the other man ... until the account was settled and I’d beaten his brains out on the carpet.  But if we meet him again, Francis, ... as, please God, we shall! ... there will be no code of honour for him ... we’ll finish him in cold blood as we’d kill a rat!”

My brother thrust out his hand at me and we clasped hands on it.

Evening was falling and lights were beginning to twinkle from the further bank of the river.

We stood for a moment in silence with the river rushing at our feet.  Then we turned and started to tramp back towards the city.  Francis linked his arm in mine.

“And now, Des,” he said in his old affectionate way, “tell me some more about Monica!”

Out of that talk germinated in my head the only plan that seemed to offer us a chance of escape.  I was quite prepared to believe Francis when he declared that the frontier was at present impassable:  if the vigilance had been increased before it would be redoubled now that I had again eluded Clubfoot.  We should, therefore, have to find some cover where we could lie doggo until the excitement passed.