“That wasn’t mentioned?” asked the Commodore.

“No.  I already knew, you see, of B45.  If just a word had been added that it was Mario who was writing to Emma Grutzner we might have identified him months ago.”

“Yes,” answered Graham soothingly and with a proper compunction.  He was not unused to other fiery suggestions from his subordinates that if only the reasons for his telegrams and the information on which his questions were based, were sent out with the questions themselves, better results in quicker time could be obtained.  Telegrams, however, were going out and coming in all day; a whole array of cipherers and decipherers lived in different rookeries in London.  Commodore Graham’s activities embraced the high and the narrow seas, great Capitals and little tucked-away towns and desolate stretches of coast where the trade-winds blew.  No doubt full explanations would have led in many cases to more satisfactory conclusions.  But fuller explanations were out of all possibility.  Even with questions fined down to the last succinct syllable the cables groaned.  None of the objections were raised, however, by Commodore Graham.  It was his business to keep men like Hillyard who were serving him well to their own considerable cost, in a good humour.  Remorse was the line, not argument.

“What a pity!  I am sorry,” protested the Commodore.  “It’s my fault!  There’s nothing else to be said.  I am to blame about it.”

Martin Hillyard began to feel some compunction that he had ever suggested a fault in the composition of the telegram.  But then, it was his business not to betray any such tenderness.

“If we could have in the future a little more information from London, it would save us a good deal of time,” he said stonily.  “Sometimes a surname is hurled at us, and will we find him, please, and cable home all details?”

“Yes, that is very wrong,” the Commodore agreed.  “We will have that changed.”  Then a bright idea appeared to occur to him.  His face lighted up.  “After all, in this instance the mistake hasn’t done any real harm.  For we have got our friend Mario Escobar now, and without these tubes and this letter from Berlin about the use of them and Jose Medina’s account of the conversation in the next room we shouldn’t have got him.  The German governess wasn’t enough.  He’s, after all, a neutral.  Besides, there was nothing definite in his letter.  But now——­”

“Now you can deal with him?” asked Hillyard eagerly.

“To be sure,” replied the Commodore.  “We have no proof here to put him on his trial.  But we have reasonable ground for believing him to be in communication with our enemies for the purpose of damaging us, and that’s quite enough to lock him up until the end of the war.”

He reached out his hand for the telephone and asked for a number.

“I am ringing up Scotland Yard,” he said to Hillyard over the top of the instrument; and immediately Hillyard heard a tiny voice speaking as if summoned from another planet.