“The clue came through the deceased man Campion, who was to have given evidence in the late trial. An unfortunate occurrence, Mr. Herriard, Campion’s fatal accident,” Quickjohn observed, in a tone of parenthetical regret; “more particularly as it was occasioned by an absolutely mistaken act on his part.”
“How so? What do you mean?” Herriard asked, in some surprise.
“Well, sir, my meaning is this,” Quickjohn answered deliberately, with the superiority of one who is sure of his facts; “it will be within your recollection that the deceased man, Campion, deposed before he died that the accident happened as he was running in pursuit of a hansom in which was a man whom he asserted he had recognized as the party he had seen leaving Vaux House under suspicious circumstances on the night of Captain Martindale’s alleged murder.”
“Yes?”
“Well, Mr. Herriard,” pursued Quickjohn, with an air of infinite witness-box wisdom, “the late Campion was quite mistaken in thinking he had recognized his man in that hansom. He could not possibly have done so, seeing that the party whom Campion had seen escaping from Vaux House on the night in question has been dead some years.”
“You know that?” Herriard asked mechanically, uncertain whether to be relieved or disappointed.
Quickjohn nodded. “Met his death shortly after the Vaux House affair. So it stands to reason that he could not have been the party whom Campion saw in the hansom.”
“Naturally. And who,” Herriard asked, with intense curiosity, “was the man we have been in search of, and who, you say, is dead?”
Mr. Quickjohn liked to tell his stories in his own way, and considered he had earned the privilege of doing so. “Well, sir,” he responded, with irritating deliberation, “it is very curious how, as every detective knows, the merest accident will often put one on the right scent. And what I have to tell you now, sir, is the result of a chance remark which fell from the late Campion. It was this way. When we heard at the Yard that he had appeared on the scene, and we knew something of what his evidence was to be, I, having charge of the case, which, on the discovery of the little weapon at Vaux House, had been placed in my hands, thought it well to have a private interview with Campion on my own account. You see, Mr. Herriard, if the Countess was innocent it was our business to find the guilty party. So I got hold of Campion and asked him to come up to my place one evening and talk the matter over quietly. He comes over to Brixton and I got from him everything that could be of the slightest use in working-up the case. You see, Mr. Herriard,” he diverged again tantalizingly, “the questions we should put are very different from those the solicitors ask; we look at the case from a working point of view. It was my object to get an idea whether the man Campion saw leaving by the window was a gentleman, likely to have been a guest, or a flash operator working the function for what he could pinch in the way of jewellery, plate, etc.”
“I see.”