And this sort of thing was destined to be Peter's experience for many days to come. Every waking hour, and many when he should have been sleeping, was spent in following up clues unearthed by eager detectives, spurred to incessant action by the large reward which Donald Morris had privately offered for any news of either or both of the sisters. Morris had been inclined, at first, to limit the reward to news of Mary. "I care nothing about the sister, Clancy," he said. "What does it matter to me where she is, or what she does? It's Mary--Mary----" The agonized appeal in his eyes was almost more than Peter could bear. The two men, so unlike, but with the bond of one common interest, had become, in those few days, fast friends. Peter could not bring himself even to hint at the sinister possibility which had presented itself to his mind and to Captain O'Malley's. Hardened as they were to the terrible crimes which were committed in this great city every day, the possibility of murder--a word which they had not whispered, even to each other--was not one which Peter would willingly suggest to the client who had become his friend. It was, therefore, with great difficulty that he persuaded Morris to make the reward applicable to news of either of the sisters. "If we can only find Anne," he said to O'Malley, after Morris had reluctantly consented, "I promise you I'll put the screws on her and find out what happened to Mary Blake, if it's necessary to have her arrested for murder to do it. You watch me! _I'm going to find Anne!_" But for once, for all his confidence in himself, Peter seemed destined to failure. Each day and all day long and far into the night, all over the country, sharp-eyed men and women trained to the last keen edge of observation and inquiry sought for the missing women. And always there were clues. Their name was legion, and Peter did not dare, in his own words, "to pass one up," for fear that it might lead true, at last. It seemed impossible that there could be so many unexplained women as were unearthed; so many women with birthmarks, so many who were young and dark, and to the observer's eager eye (dazzled, perhaps by the amount of the reward) so like the photograph which each detective carried about with him. In his investigations, Peter travelled the country over. A swift journey to St. Louis--and failure. Returning, he had no more than reached his office, when a report came in of a young woman, with a conspicuous birthmark, who had recently taken obscure lodgings in a back street in Philadelphia. The cases of those who were supposed to be Anne Blake were the most difficult to cope with and took the most time. A decision could only be reached, in some instances, by finding out the antecedents of the suspects, and by determining that the person in question was definitely in some other place on the twenty-eighth of May, for there was nothing in Peter's possession with which to identify her except a meagre description.