If so, it was a fiendish trap to set for the unfortunate dupe. French thought he could see how it was intended to pan out. Vanderkemp, while on these mysterious journeys—certainly when he reached Mr. Duke’s agent in Constantinople—would learn of the murder, and he would at once see how he had been victimised. The more he learned of the details, the more he would realise how completely he was in the toils. He would recognise that if he went home and told his story he would not have a dog’s chance of clearing himself, and he would turn his apparent flight into a real one, and so permanently fasten upon himself a tacit admission of guilt. It was an ingenious scheme, and if it really were the explanation of these mysterious happenings, it gave an indication of the character and mentality of the man who had devised it.
French was by no means decided as to the truth of the matter, but on the whole he thought that though he undoubtedly had evidence to justify him in applying for the arrest and extradition of the traveller, he would prefer to avoid this step if possible. If the man tried to give him the slip, the local police would get him in no time. Accordingly he turned once more to Vanderkemp.
“Mr. Vanderkemp,” he began, “I am strongly inclined to believe your story. But as a man of the world you will readily see that it must be more completely examined before it can be fully accepted. Now the question is, Are you willing to come back with me to London and give me your assistance towards finding out the truth? I can make you no promise that you will not be arrested on reaching British ground, but I can promise you that you will be fairly dealt with and get every chance and assistance to prove your innocence.”
Vanderkemp did not hesitate in his reply.
“I will go,” he said promptly. “I am aware that you can have me arrested here, if you want to, by applying to the Spanish authorities, so I have no choice. But I think I should go in any case. I have done nothing contrary to the law, and I have done nothing to be ashamed of. I cannot now rest until my innocence is admitted.”
French nodded gravely.
“Once again, sir, I think you are doing the wise thing. Let us go to-night by the Paris express. In the meantime come with me to the post office and help me to send a wire to the Yard.”
Two mornings later they reached London. Mr. Duke was naturally amazed at his subordinate’s story, and on hearing the evidence, gave it as his opinion that Vanderkemp was the dupe of some person or persons unknown. What was more to the point, Chief Inspector Mitchell, French’s immediate superior, took the same view, and Vanderkemp, therefore, was not arrested, though he was shadowed night and day. French undertook an investigation into his life and circumstances, which showed that these had been painted in somewhat darker colours than appeared justifiable, but which revealed no evidence about the crime. Furthermore, none of the jewels could be traced to him, nor any of the stolen notes other than those he had spoken of.
Once more the days began to slip past without bringing to light any fresh fact, and as time passed French grew more worried and despondent, and his superior officers more querulous. And then something occurred to turn his attention to a completely different side of the case, and send him off with fresh hope and energy on a new clue.