"The Enemy Within the Gates" is the fourth episode of the first series of the British comedy series Dad's Army. It was originally transmitted on Wednesday 28 August 1968, one week later than planned, due to the Warsaw Pact Invasion of Czechoslovakia.

A stranger with a suspicious foreign accent convinces Mainwairing's men that he is a Polish officer serving with GHQ who has come to inform them of a £10 reward for every Nazi arrested. While on night patrol, Jones' section capture two German airmen, but Private Godfrey complicates matters by allowing them to escape while they visit the lavatory.

Captain Winogrodzki of the Polish Forces informs the platoon that there will be a £10 reward for every live parachutist captured. Jones, Walker and Pike catch two, who escape and are caught by Winogrodzki, who announces his intention to claim the bounty for himself. But when the prisoners are collected by MPs to be taken to GHQ, Walker convinces the soldiers to take Winogrodzki too, on account of his accent. The platoon spend £5, of their £30 reward, on a celebration dinner.

In the radio version of the episode, only one German airman is captured and only £20 bounty is due after Walker persuades the MPs to additionally take Winogrodzki.

1. Nigel Rideout was given an extra £10 for writing the German dialogue in the script.^[1]
2. The episode was scheduled originally to be broadcast on 21 August 1968. However, the BBC cancelled that evening's schedule to cover the Warsaw Pact invasion of Czechoslovakia.^[2]

• "The Enemy Within the Gates" at IMDb