The real Gilbert Carstairs, Mr.Lindsey, as Mr.Portlethorpe knows, lived at Hathercleugh House until he was twenty-two years old.

He was always at Hathercleugh, except when he was at Edinburgh University studying medicine.

He knew the whole of the district thoroughly.

But, as I have found out for myself, this man does not know the district! I have discovered, on visiting him--though I have not gone there much, as I don't like either him or his wife--that this is a strange country to him.
He knows next to nothing--though he has done his best to learn--of its features, its history, its people.

Is it likely that a man who had lived on the Border until he was two-and-twenty could forget all about it, simply because he was away from it for thirty years?
Although I was only seven or eight when my brother Gilbert left home, I was then a very sharp child, and I remember that he knew every mile of the country round Hathercleugh.