Mallett pulled at his moustache and frowned. No, that didn’t seem quite to fit the case either. For if James had been working for Ballantine it must have been for some time past. By October Ballantine must have known that a crisis in his affairs was approaching. And yet it was in October that, according to this theory, he began to interest himself in James’s affairs. He turned to the other possibility—Du Pine. All that he had seen of the man and all that he had heard of him led him to believe that he was capable of most things. He had been Ballantine’s confidant and assistant in large and complex operations—therefore he was intelligent; he had been a partner to his frauds, therefore unscrupulous. But what could his motive have been for engineering his employer’s murder? Scarcely robbery. If he had been anxious to get a share in the booty which Ballantine intended to make off with, a little judicious blackmail would have served his turn, and, the inspector judged, would have been more in character than the brutal expedient of killing him. Besides, there was still the initial difficulty of solving the problem of how Ballantine came to go to James’s house. If Du Pine were responsible for James establishing himself in Daylesford Gardens, that only removed one stage further the missing connection between Ballantine and James. There could be no doubt, from his demeanour at the inquest, that the secretary was thoroughly frightened, but of what? Perhaps merely of whatever shady actions of his might come to light in the records of the “Twelve Apostles”. Possibly—but if he stood to lose by the exposure of Ballantine’s financial crookedness he would be the less likely to commit a crime which would make its discovery doubly certain. If Du Pine had plotted Ballantine’s death he would surely have had the common prudence to make his own position secure beforehand.

Casting back in his mind, he recollected something else about Du Pine—his dramatic introduction of the name of Fanshawe at the inquest. Was it a blind? If so, it was a singularly unskilful one. For he must have known that the police would not be long in discovering that James had been vouched for by the company a full month before Fanshawe was released from prison. That was yet another argument against attributing the authorship of the letter to him. Had Du Pine said the truth about Fanshawe’s visit to the office? Well, Fanshawe could help to clear that up himself. But why blurt the name out in the most public way possible, instead of quietly informing the police as any reasonable man would have done? It was almost as if he wanted to concentrate attention on Fanshawe and away from himself. Why? Or alternatively, perhaps he genuinely believed that Fanshawe had taken vengeance on Ballantine, and feared a like fate for himself in return for his share in the events of five years ago. On the whole, that theory seemed most plausible, but it left the mystery of the letter as deep as ever.