Enemy At The Door tells a story of a wartime Guernsey and the invasion and occupation by German forces. Action (and I use that term very sparingly) centres around a doctor and his family, and his relationship with the German Commandant who is, in fact a decent man. Other characters also feature such as a chief of police, and an interesting performance from Simon Cadell as an SS officer - a very different role to the wimpy one we usually associate him with in Hi-D-Hi!
Many of the stories are based around banal themes, such as livestock being poached and water quotas not being met. Some are more interesting, but all feature around dialogue, which. typically for BBC of the period, is done well. Sets are used extensively and outdoor scenes are kept to an absolute minimum. Some characters' reactions and emotions are bizarre, and unrealistic, but it is human realism upon which these episodes should be based.
What this series lacks is the depth of other series I've seen from the period, for example, Secret Army. The stories were more exciting and dealt with tenser themes; this series deals with day-to-day things that are far less interesting, as portrayed.
This DVD set also comes to a somewhat abrupt end, signalling that a third series was probably expected. Certainly the series should have planned to span the period of the war, in hindsight. So I conclude that a further series resulting in the liberation of the islands would have been envisaged by the series creators.
It's not a bad series by any means, but it also isn't a good one, and in comparison to other series of the period, it shows it could have done, and been so much more!