"Well, only that he was travelling for his health. He mentioned that he had been a great deal in South America, and was then over in Europe for a holiday. Indeed, on the first day we met, he did not even mention his name, and I quite forgot to ask for it. In travelling one meets so many people who are only of brief passing interest. It was not until a week later, when I found him staying in the same hotel as myself, the Cavour, in Milan, I learnt from the hall-porter that he was Sir Digby Kemsley, the great engineer. We travelled to Florence together, and stayed at the Baglioni, but one morning when I came down I found a hurried note awaiting me. From the hall-porter I learned that a gentleman had arrived in the middle of the night, and Sir Digby, after an excited controversy, left with him for London. In the note he gave me his address in Harrington Gardens, and asked me not to fail to call on my return to town." "Curious to have a visitor in the middle of the night," remarked the detective reflectively. "I thought so at the time, but, knowing him to be a man of wide business interests, concluded that it was someone who had brought him an urgent message," I replied. "Well, the rest is quickly told. On my return home I sought him out, with the result that we became great friends." "You had no suspicion that he was an impostor?" "None whatever. He seemed well known in London," I replied. "Besides, if he was not the real Sir Digby, how is it possible that he could have so completely deceived his friends! Why, he has visited the offices of Colliers, the great railway contractors in Westminster--the firm who constructed the railway in Peru. I recollect calling there with him in a taxi one day." Edwards smiled. "He probably did that to impress you, sir," he replied. "They may have known him as somebody else. Or he simply went in and made an inquiry. He's evidently a very clever person." Personally, I could not see how my friend could possibly have posed as Sir Digby Kemsley if he were not, even though Edwards pointed out that the real Sir Digby had only been in London a fortnight for the past nine years. Still, on viewing the whole situation, I confess inclination towards the belief that my friend was, notwithstanding the allegations, the real Sir Digby. And yet those strange words of his, spoken in such confidence on the previous night, recurred to me. There was mystery somewhere--a far more obscure mystery even than what was apparent at that moment. "Tell me what is known concerning Sir Digby's death in Peru," I asked.