When top-secret documents are stolen from an atomic power plant in Scotland, fingerprints on a briefcase are found to belong to Jock Lawson, a dock worker who sold information to the Russians in WWII before disappearing. Drake travels to a small island to investigate, but will end up disrupting the lives of all the islanders.
That's Two of Us Sorry is a retread of the earlier 25 minute episode The Gallows Tree. This is much better, benefiting from the 50 minute runtime. There's a silly sub-plot about an illegal whisky still that seems shoehorned in.
The location shooting is nice and there's a great guest cast that includes Francesca Annis, Duncan Lamont, Nigel Green, Finlay Currie and Graham Crowden. Most of them are wasted in small roles, especially Francesca Annis.
However, there's various problems with the episode, such as why someone as stupid as Graham Crowden's character would be put in charge of security at a atomic plant. The revelation at the end of where the stolen documents were was silly as well.
Overall, not one of the best examples of the series, but it's entertaining.