Roscoe watched Justine Caron as she passed out into the shade of the woods, and he said to himself: “Gratitude like that is a wonderful thing.” He should have said something else, but he did not know, and she did not wish him to know: and he never knew. CHAPTER XVI. A DUEL IN ARCADY The more I thought of Mrs. Falchion’s attitude towards Roscoe, the more I was puzzled. But I had at last reduced the position to this: Years ago Roscoe had cared for her and she had not cared for him. Angered or indignant at her treatment of him, Roscoe’s affections declined unworthily elsewhere. Then came a catastrophe of some kind, in which Alo (whoever she was) suffered. The secret of this catastrophe Mrs. Falchion, as I believe, held. There was a parting, a lapse of years, and then the meeting on the ‘Fulvia’: with it, partial restoration of Mrs. Falchion’s influence, then its decline, and then a complete change of position. It was now Mrs. Falchion that cared, and Roscoe that shunned. It perplexed me that there seemed to be behind Mrs. Falchion’s present regard for Roscoe some weird expression of vengeance, as though somehow she had been wronged, and it was her duty to punish. In no other way was the position definable. That Roscoe would never marry her was certain to my mind. That he could not marry her now was also certain--to me; I had the means to prevent it. That she wished to marry him I was not sure, though she undoubtedly cared for him. Remained, therefore, the supposition that if he cared for her she would do him no harm, as to his position. But if he married Ruth, disaster would come--Roscoe himself acknowledged that she held the key of his fortunes. Upon an impulse, and as a last resort, I had taken action whereby in some critical moment I might be able to wield a power over Mrs. Falchion. I was playing a blind game, but it was the only card I held. I had heard from the lawyer in Montreal that Madras, under another name, had gone to the prairie country to enter the mounted police. I had then telegraphed to Winnipeg, but had got no answer. I had seen her many times, but we had never, except very remotely, touched upon the matter which was uppermost in both our minds. It was not my wish to force the situation. I knew that my opportunity would come wherein to spy upon the mind of the enemy. It came. On the evening that Justine Caron called upon Roscoe, I accidentally met Mrs. Falchion in the grounds of the hotel. She was with several people, and as I spoke to her she made a little gesture of invitation. I went over, was introduced to her companions, and then she said: “Dr. Marmion, I have not yet made that visit to the salmon-fishers at Sunburst. Unfortunately, on the days when I called on Miss Devlin, my time was limited. But now I have a thirst for adventure, and time hangs heavy. Will you perform your old office of escort, and join a party, which we can make up here, to go there to-morrow?”