The quiet seaside town of Mablethorpe was an unlikely location for what appeared to be an organised hit on a couple in their 50s. Emilia travels to the Lincolnshire coast to learn about the violent murders of Joan and John Stirland in 2004. These were murders that had links to organised crime in Nottingham, and the investigation into the deaths led to the downfall of one of Nottinghamshire's most feared underworld figures. Murdertown returns for a fourth season, this time hosted by award-winning actress Emilia Fox. In each episode, Emilia will visit towns and local communities throughout the country rocked by murder and tragedies, from which the scars persist to this day. Through the testimony of investigating police officers, local journalists, friends and relatives, the series re-tells these shocking incidents and how the lives of those directly affected will never be the same again.