Agatha Christie's Seven Dials Season 1

The year is 1925. A celebration at the Chimneys country estate ends in tragedy: one of the guests dies mysteriously, and the killer leaves seven alarm clocks by the body. The police are baffled and offer no leads while Superintendent Battle is preoccupied with examining the crime scene. That is when Eileen Brent, a young and inquisitive aristocrat, decides to launch her own investigation.