He had emigrated to America when he was a very young man.
He had prospered well, and Barker had first met him in California, where they had become partners in a successful mining claim at a place called Benito Canyon.

They had done very well; but Douglas had suddenly sold out and started for England.

He was a widower at that time.

Barker had afterwards realized his money and come to live in London.

Thus they had renewed their friendship.
Douglas had given him the impression that some danger was hanging over his head, and he had always looked upon his sudden departure from California, and also his renting a house in so quiet a place in England, as being connected with this peril.