From the messageboard on Anthony Horowitz’s website, sentiments that echo mine:
I’ll tell you why I would welcome a continuing Barbara Hicks storyline: I think that she was the only woman character that Foyle clearly connected with in a heart to heart, soulful sense in the series. They even seemed to be able to comfort each other – both had suffered deeply felt loss in their lives and Mr. Foyle had kept his wounds well hidden until he met Barbara Hicks. Mr. Foyle emotionally revealed himself to her seemingly without holding back, a fundamental deviation from his rigid sense of privacy, something he had not done with any other character in the series, including his son.
I thought the Barbara Hicks scenes were Mr. Horowitz’s finest writing of the series. I thought the dialogue was true to the characters, very unexpected, beautifully understated, and yet compelling…
Yes, the writer of They Fought in the Fields certainly hit it out of the park. Only credit goes to Rob Heyland rather than AH. I suspect AH was more than happy to have someone else create some romance for Foyle. Stella Gonet and Michael Kitchen did every justice to the script with their moving performances.