If that were the explanation, it was plain that Grantley had proved false to the bargain. He had not only destroyed the check—which seemed to confirm Nick’s theory that he was not entitled to it, but was expected to pass it on to some one else—but he had, also, by sending the fragments to Nick, given the detective a broad hint that he was looking elsewhere for his pay.
Nick did not believe that Grantley had meant to do any more than indulge in a dramatic defiance, but that was the effect his act had had.
As for his apparent breaking of faith with his unknown confederate, that presented no great difficulties. Grantley would have been quite capable of such an act if he had already received his pay from that quarter. It would have meant neither financial loss nor physical danger to himself, and that was all that would have deterred him.
To make a long story short, the great detective had set to work along this line. With Grantley and his known accomplices safely in custody, he had ample time to carry the investigation as far as necessary.
It is enough to say that it confirmed his theories one after another.
First, he discovered that Doctor Grantley’s original motive had been one of private revenge, of a twofold character. The surgeon’s real name was not Grantley at all, but Standish. He had inherited quite a large sum of money, and, in their younger days, he and Baldwin had both loved the same girl. She had married the future financier and died a few years later.
Standish had foolishly blamed Baldwin for the girl’s preference, and had never forgiven him. He had subsequently changed his name to Grantley, which explained the fact that Baldwin had not suspected his identity.
Years afterward, Grantley, as he then called himself, had invested heavily in a certain copper company, not knowing that the corporation was secretly controlled by the blind financier. The venture happened to be one of Baldwin’s few failures, and Grantley had lost his entire investment.
Afterward, when he had learned of Baldwin’s connection with the punctured bubble, he had gone nearly mad with rage and the thirst for vengeance.
He had bided his time, however. After his sensational trial on the charge of manslaughter, he had decided that the time was ripe. His practice was already ruined, and he had little more to lose, whatever happened.