Dad's Army seemed to be on an irrecoverable slide since James Beck, who played Private Walker, died, his last appearance being in S6 E6. Walker was easily the best character: his shady "business" activities, snide remarks and other one-liners made the show. His replacement, Cheeseman the War Correspondent, didn't make the grade at all.
It wasn't just that. The writers appeared to have run out of ideas, repeating old gags and resorting to silly plots.
So imagine my surprise when this episode came along. It's absolutely brilliant. The inane situation of the platoon dressing up as German soldiers and being mistaken for Germans gives the writers free rein with the plot and Dad's Army (and humour in general) works best when it is absurd.
The even bigger surprise is that the centre of the hilarity, the funniest figure in a very funny episode, is Pike. He is usually the most annoying character in the show but here he is the star, revelling in pretending to be a German officer.
Wonderfully funny.