“My next condition,” I said slowly, “is that you give me your entire confidence. There must be nothing kept from me. You must tell me all—absolutely all.”

“Ah, but—that is impossible,” he replied gently. “I simply dare not reveal the details of the secret, which I want you to work on, to any single soul. If I did, my life would be taken within the following four and twenty hours.” And all at once he shivered, as though he had himself caught instinctively some eerie presentiment of his doom.

“But how can I hope to work successfully in the dark?” I cried, throwing up my hands.

“Easily enough,” he returned. “All you have to do is to carry out my instructions, then nothing need be feared. For instance, here is the first task which I desire you should undertake.” And again he put his hand in his breast pocket, and this time he did not produce a pocket-book, but a tiny cutting which he explained came from that evening’s Globe, and which set out this odd notice:

To be sold—without Reserve—the Library and Effects of a Refugee Spanish priest, lately deceased. Contains many early printed Books, Horae, Liturgical, and other Manuscripts. By Auction to-morrow (Friday) at 3 PM. The Bromley Mart, King’s Street, Covent Garden, WC.

Now, almost in spite of myself, I felt flattered by this quaint and unexpected turn of negotiations which dropped so suddenly a mystery and touched on concrete things.

Let me explain the reason. As a matter of fact, if there was one hobby at that moment that appealed to me more than another it was that connected with old books, old furniture, old silver, old deeds, and charters. Indeed, I admit freely, I had attained already some certain amount of notoriety amongst the well-informed in this direction, acting as I had done for the young Earl of Fotheringay before I became a secret investigator, and at a time when I had leisure to roam from auction mart to curiosity shop, and thence to old country mansions on the eve of important sales—where more bargains in antiques are picked up than most wealthy curio-collectors dream of. But how Don José could have guessed I had any specialist knowledge of this sort I was powerless to explain. None the less, the probability of some romance, or some rare discovery in this sale, tempted me sorely, and the Spaniard, who had been narrowly watching my features, seemed to divine that, to recognise that I was then almost as good as won to his cause, for all at once he lowered his eyes before me, but not before I caught in their deep, dark depths the glint of some conscious triumph.

“So you wish me to bid for these things,” I at length suggested tentatively, laying the cutting on the table and tapping it interrogatively. “All of them or some?” I asked after another moment’s pause.

“One lot. Number 82, a bundle of manuscripts. These are very valuable.” And again his eyes flashed.

“What limit may I go to?”