To solve an impossible murder, you need an impossible hero - Judith Potts is seventy-seven years old and blissfully happy. She lives on her own in a faded mansion and to keep herself busy she sets crosswords for The Times newspaper. One evening, while out swimming in the Thames, Judith witnesses a brutal murder. The local police don't believe her story, so she decides to investigate for herself... A new cosy crime series from the creator of the hit TV series 'Death in Paradise'.