Dad's Army: The Lost Episodes - Season 1 - Eps 3: Under Fire
Whilst on fire-watching duty the platoon see a man shining a torch. He speaks with a European accent and has a dog called Fritz and they arrest him as an enemy agent. However, the man - Sigmund Murphy - tells them that he is a British subject and even helps them put out a fire in the church hall, after which Hodges explains that Sigmund is indeed a British citizen and the husband of his Auntie Ethel.
About Dad's Army: The Lost Episodes

Title: Dad's Army: The Lost Episodes
First Air Date: 2019-08-25
Last Air Date: 2019-08-27
Status: Ended
Rating: 8/10 (from 3 votes)
Language: EN
Seasons: 1
Total Episodes: 3
Network: Gold
Genres: Comedy
Production Companies: Unknown
Synopsis
Dad’s Army is Britain’s favourite sitcom but 3 of the original 80 episodes have been lost. Now, using the original scripts by Jimmy Perry and David Croft, those three episodes have been recreated as faithfully as possible and come to the screen for the first time since 1969. The brilliant new cast includes Kevin McNally as Captain Mainwaring, Robert Bathurst as Sergeant Wilson, Kevin Eldon as Lance Corporal Jones, David Hayman as Private Frazer, Mathew Horne as Private Walker, Timothy West as Private Godfrey and Tom Rosenthal as Private Pike.
Cast

Mathew Horne
Private Walker

Kevin McNally
Captain Mainwaring

Kevin Eldon
Corporal Jones

Timothy West
Private Godfrey

Tom Rosenthal
Private Pike

Robert Bathurst
Sgt Wilson

David Hayman
Private Frazer