I enjoyed this episode. It had shades of "The Man Who Haunted Himself" where Brett was questioning his own sanity.
Brett was friends with a very rich but reclusive business man, who was about to visit London. (Played by Bernard Lee, "M" in the Bond movies.) Brett had been taken to a make believe hospital, after supposedly having a bad accident. While there he was programmed to kill the friend, when he heard certain words. His wife and others were in on the plot.
To test Brett, to see if he was ready, the baddies set him up to attack Danny, which he did, but something stopped him from actually killing him. The day when Brett was just about to kill his friend, Danny stopped him in the nick of time.
I liked how Roger was allowed to play a range of emotions, so different from his usual light-hearted delivery.
