The narrative podcast remains a form in search of a genre. The template set by the hit show Serial — enterprising American journalists with janky piano theme tune shed new light on tantalising murder — still predominates seven years on. To this we can add the format pioneered by S-Town (initial murder investigation subsides into rich human detail) and, more recently, the excellent Wind of Change (intriguing what-if maps cultural and macropolitical shifts, with bonus CIA window-dressing).