Wow! A TV series we totally enjoyed.
The stories, complicated and unpredictable, were all interwoven, and in the end - but not until the end - always all wrapped up and the case(s) solved - usually in the way you least expected it, but making total sense. The actor playing Detective Foyle does an amazing job. Very often he didn't say a word, but we could tell what he was thinking just from his expressions. Other times he delivered gut-punching lines ("I've figured out what you did and how you did it") with a perfectly straight face.
For us it was eye-opening, learning about WWII from the English point of view. There were many thought-provoking topics as various characters consider what would be the best course of action, and experience character-building events in their lives. I love learning something while being entertained.
Other reviews mentioned lack of captions; we watch everything with captions (although the actors in this series speak clearly enough for us to understand them better than most with an accent different from our own), and I believe there are now captions on all discs in every season of this series.