| Series: | Dad's Army |
| Series No: | 4 |
| Episode: | 13 |
| Director: | David Croft |
| Story: | Jimmy Perry and David Croft |
| Producer: | David Croft |
| Length: | 34 minutes |
| Prev: | Uninvited Guests |
| Next: | Battle of the Giants! |
"Fallen Idol" is the thirteenth and final episode of the fourth series of the British comedy series Dad's Army. It was originally transmitted on Friday 18 December 1970.
Captain Mainwaring has always epitomised the principle of military sobriety to his men, but, after Captain Square leads him astray one day in the Officer's Mess, he ends up inebriated. Only something genuinely heroic now can restore his damaged reputation in the eyes of his men.
The Walmington-on-Sea platoon arrive at a weekend country training camp to learn about handling bombs. The camp is run by the twitchy Captain Reed, who is frightened by the enthusiasm and lack of awareness shown by the Home Guard units. He is particularly unsettled by the Walmington platoon, especially Corporal Jones.
As the men bring their bedding into their bivouac tent, Private Pike tries to find his teddy bear, Mr. Snuggly. When Sergeant Wilson finds it, Mainwaring notices and Wilson reluctantly claims that the bear is his, so as not to embarrass Pike. Meanwhile, Jones has brought a mosquito net, despite Walker telling him there are not any around. Jones explains that he has had the net since his Sudan days, and that it helped to keep out snakes as well during cold nights.
Captain Square enters and convinces Mainwaring to set up an officers only section in the tent for himself and Wilson, much to the outrage of the men. He subsequently offends them by attending a select officers mess, drinking whisky with Square and his two colleagues, and playing "Cardinal Puff" while his men enjoy a couple of bottles of ale elsewhere. Most of the men are disgruntled, while noting this is not Mainwaring's normal behaviour. Frazer goes so far as to threaten to resign (his general surly attitude of late has led Mainwaring to suspect he is a communist, noting he "never plays Monopoly with the others" as evidence of his suspicions). After the men go to bed, a drunken Mainwaring returns to their tent only to be jumped on by Jones, thinking he is a thuggee.
The next morning, a rather hungover and worse for wear Captain Mainwaring joins his men for training. While at first things go seemingly to plan, potential disaster soon strikes when a stray grenade is fired into the roof of Jones's van. He starts to drive away, so Mainwaring gives chase on a bicycle, gets into the van and warns Jones, who abandons the van while it is moving. A cool Mainwaring then stops and evacuates the van, but it is stood next to power lines. Mainwaring immediately re-enters the van and recovers the grenade: his command of the situation restoring his reputation in the eyes of the platoon. After Mainwaring throws the grenade away and dives for safety he hears panting, looking up to see the grenade being held by a shaggy dog. Mainwaring flees, only to be chased down the road by the dog as the episode ends.