This is a hugely enjoyable but, in some ways, strange sit-com, which I have seen more than once and still enjoy.
It provides an interesting solution to the two problems that sit-coms face: if you depend on getting a laugh from every line, what do you do with the inevitable dud lines; and if you depend on a new comic situation each week, what happens when you run out of comic-situation ideas? Even the greatest comedies (such as Dad's Army or Yes Minister) fail on one or both of these counts eventually.
The solution to the first problem here is that not every line is pummelled into a gag; conversations, particularly between the two main characters, develop realistically and the humour emerges: sometimes several consecutive laugh-lines, sometimes just one in an interchange; sometimes just a whimsical look is enough to end an interaction with humour.
The solution to the second problem is related to and helps with the first: there is a continuing narrative to the series surrounding husband (Peter Egan) and wife (Hannah Gordon). Episode-based sub-plots are present but don't have to carry the whole episode alone so the overall feel is one of a comedy tending at times towards a comedy-drama but still rooted nearer comedy than drama.
Neither of the two stars is really an out-and-out comedy player but that is key, given what I have described above: it needs dramatic actors who can do subtle comedy.
The incomparably gorgeous and wonderful Hannah Gordon barely has to speak a word to hold the screen and can easily run the gamut of all the emotions needed to sustain the comedy and the pathos without any hint of effort. Peter Egan is more limited in his range but suits the part-cynical, part-vulnerable, part-inspiring husband very well here.
By contrast, the real pure-comedy star is John Bird; his paranoid, put-upon assistant bank manager is vintage Bird and a comedic joy.
