“I don’t know what you mean,” he said bluntly.
“God bless my soul!” ejaculated Mortimer turning round to stare at him through his grotesque glasses. And then he said very deliberately in German:
“War niemand da?”
Desmond stood up promptly.
“What do you want with me?” he asked quietly, “and why do you speak German in my house?” Mortimer gazed at him blankly.
“Excellence, most excellent,” he gasped. “I love prudence. My friend, where are your eyes?”
He put a large, firm hand up and touched the upper edge of the left lapel of his jacket. Desmond followed his gesture with his eyes and saw the other’s first finger resting on the shiny glass head of a black pin. Almost instinctively Desmond imitated the gesture. His fingers came into contact with a glassheaded pin similarly embedded in the upper edge of the lapel of his own coat.
Then he understood. This must be the distinguishing badge of this confraternity of spies. It was a clever idea, for the black pin was practically invisible, unless one looked for it, and even if seen, would give rise to no suspicions. It had obviously escaped the notice of the Chief and his merry men, and Desmond made a mental resolve to rub this omission well into his superior on the first opportunity. He felt he owed the Chief one.
Mr. Mortimer cleared his throat, as though to indicate the conclusion of the episode. Desmond sat down on the settee.
“Nothing came while I was away!” he said.