If he thought Strange had found the ore, it would obviously be impossible to learn anything about it after the man was drowned.

The theory that Strange had already told him where the lode was, and Driscoll meant to get rid of a partner who would demand the largest share, must be rejected, since if Strange had told him, Driscoll would have gone away to register the claim.

But he had not done so.
The thing was mysterious, and Thirlwell could see no light.

He must wait and watch for a hint, and in the meantime resolved to talk to Scott about it.

So far, he had rather avoided the subject of Strange's death, but it might be better to abandon his reserve.