The tall writer Steven Poole opened the wooden door of the strong house and peered at the small figure on the stone doorstep. It was a boy. Cradled in his palms the boy nervously proffered a startling object. It was the new book by the famous novelist Dan Brown.

The tall writer took the precious artefact from the nervous boy’s hands and thanked him. The miniature human scuttled off. An idling engine revved into life. The writer glanced down the street, then retreated into the residential building. He knew he had better get to work. Looking at his Tag Heuer Swiss watch, he calculated that he had only 48 hours to decode the arcane puzzle of the bestselling author’s latest novel.