community of escaped Spanish slaves who were being marched north to build a wall. Garner recognised this as a potential garbled reference to the famous lost Ninth Legion of Rome, also called "The Spanish Legion". He believed that at the time the Legio IX Hispana disappeared, the emperor Hadrian had ordered the building of the stone barrier, Hadrian's Wall. From this he concocted the idea that the Ninth had been sent to build the wall but some went AWOL on the way, settling on Mow Cop; the basic premise for the Rome-era portions of the novel. Garner explains that this scenario immediately brought to his mind the unrelated event of the Barthomley massacre, the first connection between different historical periods that informs Red Shift. Finally, Garner saw some graffiti in a train station that said, in chalk, two lovers' names; beneath, however, was written in lipstick "not really now not any more". Upon reading this, all of the above-mentioned bits came back to him in a flash, and he wrote the novel. Television adaptation and popular culture In 1978 the BBC produced Alan Garner's own script adaptation of the story as an episode in the Play for Today series. Directed by John Mackenzie, the play was transmitted 17 January 1978. It was released on DVD by the British Film Institute in September 2014. The novel, including the Vigenère cipher used in the novel, is the theme of Listener crossword 4340, Red Shift. Coded message The end papers of the book are covered with a coded message. In the story, Tom and Jan write letters to each other in ciphertext, using a method they find in works by Lewis Carroll. Although we are not told of Tom's suggestion for a key, the message can be intuitively decoded and the code's key can then be identified as being "Tom's a-cold", representing his isolation and loneliness. This is itself a quote from King Lear (Act III, Scene iv) and is a phrase which appears elsewhere in the book during shift sequences. The message in the end papers should be decoded using the key sequence "TOMSACOLD". The decoded message is: I love you. If you can read this you must care. Help me. I'm writing before we meet, because I know it'll be the last. I'll put the letter in your bag, so you'll find it on the train afterwards. I'm sorry. It's my