There are few things quite as unconvincing as a train carriage with a CSO background, but during this era of television you did tend to see it a lot – unless you could afford the money to shoot on location, there was no other way round this problem.

In a strange way I find this sort of thing quite comforting though and it’s never bothered me (if you’re quibbling about how things look, rather than the script and the actors, then things aren’t going very well).

Mainwairing and the others are en route to a weekend training course. As it’s a long journey, Godfrey is feeling the strain (Jones helpfully tells him to recite a poem to take his mind off things, but Godfrey’s choice – The Owl and the Pussycat – isn’t a good one). I like the fact that Frazer – on both the inward and outward journeys – is knitting, but no-one comments on this (I wonder what he was making?)

Arriving at the railway station, Mainwairing opens his sealed orders and, after studying the map, is pleased that the camp is only a mile away. He confidentially tells the men that they’ll be there in no time – but by this point in the series’ history,  the audience should be primed to expect that he’ll get them hopelessly lost. Which he does ….

Another interesting titbit is that the platoon whistle the Dad’s Army theme as they march round and round in circles.

Finally they reach their destination, only to find out that they’ve missed supper and even worse, they’re in the hands of Captain Rodrigues (Alan Tilvern), an uncouth foreigner. Alas, Tilvern’s not got a great deal to work with as Rodrigues simply spends all his time barking at the platoon (who he regards with the upmost contempt).

The battle ground will be instantly recognisable since it’s where the colour closing titles were shot. It’s surprising to be reminded that some of the end title footage (the final scene of Mainwairing and co running towards the camera) was used in this episode first and not shot specially.

A generous helping of Battle School was made on film (as we wiitness Mainwairing, leading from the front, suffering one disastrous reversal after another). There’s something really odd about these training scenes though – Walker has nipped off to a nearby farm to steal some food, but although we see Joe unsuccessfully attempting to rustle an animal or two, whenever we cut back to the platoon he’s also there. It’s really hard to understand why this wasn’t spotted during filming (unless the farm scenes were shot later to pad out an underrunning episode?)

Having taken one humiliating knock too many, Mainwairing elects to capture Rodrigues’ HQ and wipe the smile off his face. This he does, although it all happens rather too easily (and we don’t even see Rodrigues’ reaction, which was a missed opportunity).

Not the best episode the series has to offer then, but it still has a number of good moments. For example, I adore Rodrigues ordering Jones to stuff his palliasse with straw – that sort of thing was always a gift for Clive Dunn.