I remember watching these late night probably in the early 80s in reruns in the US. I was too young during their original run, (3-7 years old), and we had moved by the time I recall watching these. My mother loved Brian Clemens. I'm on season 1 on Prime and thoroughly enjoying it. I just finished Murder in Mind and guessed it from the start, having been an avid Agatha Christie reader, however, it's so well acted that still doesn't matter. Donald Gee has been in so many things, including Doctor Who. I really miss good mystery and horror anthology series.
Review of Thriller
