In the novel And Then There Were None, Matthews, KC was the defence lawyer in the trial of Edward Seton. He conducted the defence masterfully. Edward Armstrong who knew Matthews had met him at a restaurant on one of the days during the trial. Matthews had been confident and was sure that Seton would be acquitted. At the end of the trial, Matthews delivered an excellent closing argument which made a good impression on the jury and which the prosecuting counsel Llewellyn had failed to rebut. Yet the jury eventually found Seton guilty. Matthews commented on this to Armstrong, saying that this was due to the judge Lawrence Wargrave who turned the jury right around, almost as though he had a private emnity towards Seton. Nonetheless, for all that, Matthews felt that everything was quite legal. Wargrave, in his opinion, knew the law well.