This series ends with no doubts or questions. It'sa bitter sweet ending a difficult to watch if you've become a fan of the title characters. Imagine if The Avengers ended with John Steed and Tara King being shot into orbit....oh wait. That did happen. Well, imagine if they made it seem gloomy. Sapphire and Steel by this episode are with Silver and they're targeted by the transuranics who were hired by the trios own superiors to destroy them.
Assignment 6 has some interesting concepts. It's a 70s-80s British sci fi show so naturally the special effects are terrible. The story itself is suppose to keep you interested and it succeeds in this last 4 parter. Funny how the Brits now have great special effects for their sci fi shows but terrible scripts.
Sapphire and Steel had some ups and downs. The first assignment made it seem like a kids show. Second was two episodes longer and more adult. Third had a truly twisted story to bring home the message of animal cruelty. Fourth assignment is a 4 parter and likely the best in the series about an entity that inhabits every photograph being released into 20th century earth, fifth assignment is the least liked story which plays like an overlong drawing room murder mystery, this sixth assignment is strong but as I said, bittersweet if you're a fan. Maybe I imagine Val Pringle's Lead making an appearance in an imaginary 5th episode to save the day. I remember it was something the creators mentioned as a possibility had the series been renewed.
I like the acting, the duplicity of the villains has passed and its a race against time by this final episode.