Some time later Stevenson and his wife together wrote a play called _The Hanging Judge_.

In this, the title character is tempted for the first time in his life to tamper with the course of justice, in order to shield his wife from persecution by a former husband who reappears after being supposed dead.

Bulwer's novel of _Paul Clifford_, with its final situation of the worldly-minded judge, Sir William Brandon, learning that the highwayman whom he is in the act of sentencing is his own son, and dying of the knowledge, was also well known to Stevenson, and no doubt counted for something in the suggestion of the present story.
Once more, the difficulties often attending the relation of father and son in actual life had pressed heavily on Stevenson's mind and conscience from the days of his youth, when in obeying the law of his own nature he had been constrained to disappoint, distress, and for a time to be much misunderstood by, a father whom he justly loved and admired with all his heart.

Difficulties of this kind he had already handled in a lighter vein once or twice in fiction--as for instance in the _Story of a Lie_ and in _The Wrecker_--before he grappled with them in the acute and tragic phase in which they occur in the present story.
These three elements, then, the interest of the historical personality of Lord Braxfield, the problems and emotions arising from a violent conflict between duty and nature in a judge, and the difficulties due to incompatibility and misunderstanding between father and son, lie at the foundations of the present story.

To touch on minor matters, it is perhaps worth notice, as Mr.Henley reminds me, that the name of Weir had from of old a special significance for Stevenson's imagination, from the traditional fame in Edinburgh of Major Weir, burned as a warlock, together with his sister, under circumstances of peculiar atrocity.
Another name, that of the episodical personage of Mr.Torrance the minister, is borrowed direct from life, as indeed are the whole figure and its surroundings--kirkyard, kirk, and manse--down even to the black thread mittens: witness the following passage from a letter of the early seventies:--"I've been to church and am not depressed--a great step.