“I am thinking,” I replied honestly, “that we are about of an age. That if Nanette had looked at me as I saw her looking at you, I should have asked her to marry me before I let her go back to her seat.” He stared very hard, his expression changing from second to second; then: “Being Celtic,” he said, “I suppose I am superstitious. At every turn since I have met her Nanette has intruded in my life. I am beginning to wonder.” “About what are you thinking in particular?” I asked. “About the letter that Zara dropped in the cab and that Nanette gave to you.” “Have you fathomed it?” I asked excitedly--“and the other?” “Both are in the same code. But without the first I doubt that I should have been able to read the second.” “Then you _have_ read them?” “I have,” O’Shea replied; “and this time Nanette has dealt me a full hand.” His suppressed excitement communicated itself to me. “What have you learned?” I said eagerly. “Can I be of any assistance?” “Your assistance is indispensable!” he returned. “Are you game?” “Every time!” “Good enough. Let us go along to your rooms, and I will explain what to-night has in store for us.” As the taxi that we presently hailed threaded its way through the traffic of Cranbourne Street, and on through that of Piccadilly, I glanced aside several times at my silent companion. I wondered if his abstraction might be ascribed to the problem of the S Group, or to that of Nanette. Not being an O’Shea, I hesitated to judge. But my vote was for Nanette. Arrived at my rooms and having sampled the whisky and soda: “Now,” O’Shea began, “the mantle of Edgar Allan Poe not having fallen upon my shoulders, I doubt that I should have solved this cipher but for the happy coincidence of meeting our German friend in the very shadow of Peter Pan. You will recall, too, that at the moment of his departure, the clocks were chiming the hour of noon.” “I remember,” said I. “I turned it over in my mind, considering the thing from every conceivable angle. Before I tackled the cipher--for of course the messages were palpably written in some kind of cipher--one fact was plain enough to me.” “What was that?” “The fact that Zara, an important member of the S Group, was not known by sight to the member who spoke to us! He mistook _me_ for Zara, and he mistook _you_ for one Comrade Wilson, of whom I had never heard, and respecting whom I have no instructions.” “So far I agree,” said I, “but what I simply cannot make out is why this deranged German should walk up to two perfect strangers seated in Kensington Gardens and take it for granted that they were the people he was looking for.” “His opening remark was non-committal,” O’Shea reminded me, reflectively sipping his whisky and soda. “Certainly it was; but am I to assume that the man was walking about London addressing the inquiry, ‘Have you seen Comrade Zara?’ to every male citizen he met on his travels?”