At last I spoke.

“What’s all this rigmarole got to do with Francis, Dicky?” I asked, vainly trying to suppress the bitterness in my voice.  “This looks like a list of copybook maxims for your Dutch friend’s advertisement cards....”

But I returned to the study of the piece of paper.

“Not so fast, old bird,” Dicky replied coolly, “let me finish my story.  Old Stick-in-the-mud is a lot shrewder than we think.

“‘When I read the writing,’ he told me, ’I think he is all robbish, but then I ask myself, Who shall put robbish in my invoices?  And then I read the writing again and once again, and then I see he is a message.’”

“Stop, Dicky!” I cried, “of course, what an ass I am!  Why Eichenholz....”

“Exactly,” retorted Dicky, “as the old Mynheer was the first to see, Eichenholz translated into English is ‘Oak-tree’ or ’Oak-wood’—­in other words, Francis.”

“Then, Dicky....”  I interrupted.

“Just a minute,” said Dicky, putting up his hand.  “I confess I thought, on first seeing this message or whatever it is, that there must be simply a coincidence of name and that somebody’s idle scribbling had found its way into old van U.’s invoice.  But now that you have told me that Francis may have actually got into Germany, then, I must say, it looks as if this might be an attempt of his to communicate with home.”

“Where did the Dutchman’s packet of stuff come from?” I asked.

“From the Berlin Metal Works in Steglitz, a suburb of Berlin:  he has dealt with them for years.”

“But then what does all the rest of it mean ... all this about Achilles and the rest?”

“Ah, Desmond!” was Dicky’s reply, “that’s where you’ve got not only me, but also Mynheer van Urutius.”

“’O oak-wood!  O oak-wood, how empty are thy leaves!’....  That sounds like a taunt, don’t you think, Dicky?” said I.

“Or a confession of failure from Francis ... to let us know that he has done nothing, adding that he is accordingly sulking ’like Achilles in his tent.’”

“But, see here, Richard Allerton,” I said, “Francis would never spell ‘Achilles’ with one ‘l’ ... now, would he?”

“By Jove!” said Dicky, looking at the paper again, “nobody would but a very uneducated person.  I know nothing about German, but tell me, is that the hand of an educated German?  Is it Francis’ handwriting?”

“Certainly, it is an educated hand,” I replied, “but I’m dashed if I can say whether it is Francis’ German handwriting:  it can scarcely be because, as I have already remarked, he spells ‘Achilles’ with one ‘l.’”

Then the fog came down over us again.  We sat helplessly and gazed at the fateful paper.

“There’s only one thing for it, Dicky,” I said finally, “I’ll take the blooming thing back to London with me and hand it over to the Intelligence.  After all, Francis may have a code with them.  Possibly they will see light where we grope in darkness.”