My guest this week says his novel was written in a trance. He rented an attic from a musician, who he could hear practising in the rooms downstairs, brought along a cageful of finches and set them free to fly around him as he typed. You’ll see from the title why they seemed like a good idea. These avian muses were also treated to the soundtracks of several movies – Rosemary’s Baby, The Fog and Creepshow – which doubtless helped them get further into character. When he needed to crank up the intensity, there would be two songs howling at once – the radio at one end of the room, classical music at the other. My guest reports that sometimes his birds got tired and stared at him. This endearing aural vandal is Josh Malerman, his novel is the post-apocalyptic thriller Bird Box, and he’ll be here on Wednesday with his Undercover Soundtrack.