He delayed no longer, but hurried down the side street by which the north road leaves the town.
He had crossed the bridge of Lochan and was climbing the steep ascent which led to the heathy plateau separating that stream from the Garple before he had got his mind quite clear on the case.

FIRST, Loudon was in the plot, whatever it was; responsible for the details of the girl's imprisonment, but not the main author.

That must be the Unknown who was still to come, from whom Spidel took his orders.

Dobson was probably Loudon's special henchman, working directly under him.

SECONDLY, the immediate object had been the jewels, and they were happily safe in the vaults of the incorruptible Mackintosh.