I listened to this one over a period of days as I walked home from work, which was probably a good thing, given the circular, repetitive nature of the story. It's an Edwardian house murder puzzle, except unlike an Agatha Christie novel, this one has issues with Time. It had some delightfully creepy moments, but I don't think the ending solution had enough...I don't know, wow factor. The tag was predictable. Still, a neat structure overall.
List of DW audio titles and their chronology in relation to the television series.