"Quite!" answered Purdie. "I understand it exactly." "Then my theory is, that Parslett saw the real murderer of Daniel Multenius come out of Multenius's side-door, while he, Parslett, was standing at his own; that he recognized him, that he tried to blackmail him yesterday, and that the man contrived to poison him, in such a fashion that Parslett died shortly after leaving him," said Ayscough, confidently. "It's but a theory--but I'll lay anything I'm not far out in it!" "What reason have you for thinking that Parslett blackmailed the murderer?" asked Purdie. "This!" answered the detective, with something of triumph in his tone. "I've been making some enquiries already this morning, early as it is. When Parslett was picked up and carried to the hospital--this St. Mary's Hospital, close by here--he was found to have fifty pounds in gold in his pocket. Now, according to Parslett's widow, whom I've seen this morning, Parslett was considerably hard up yesterday. Trade hasn't been very good with him of late, and she naturally knows his circumstances. He went out of the house last night about nine o'clock, saying he was going to have a stroll round, and the widow says she's certain he'd no fifty pounds on him when he left her--it would be a wonder, she says, if he'd as much as fifty shillings! Now then, Mr. Purdie, where did a man like that pick up fifty sovereigns between the time he went out, and the time he was picked up, dying?" "He might have borrowed it from some friend," suggested Purdie. "I thought of that, sir," said Ayscough. "It seems the natural thing to think of. But Mrs. Parslett says they haven't a friend from whom he could have borrowed such an amount--not one! No, sir!--my belief is that Parslett saw some man enter and leave Multenius's shop; that he knew the man; that he went and plumped him with the affair, and that the man gave him that gold to get rid of him at the moment--and contrived to poison him, too!" Purdie considered the proposition for awhile in silence. "Well," he remarked at last, "if that's so, it seems to establish two facts--first, that the murderer is some man who lives in this neighbourhood, and second, that he's an expert in poisons." "Right, sir!" agreed Ayscough. "Quite right. And it would, of course, establish another--the innocence of your friend, Lauriston." Purdie smiled. "I never had any doubt of that," he said.