Potts accidentally puts his superior commander request for short holiday on the pile of applications for the suicidal mission behind enemy lines.
It appears the Germans have a spy inside the bunker and everyone is trying to figure out who the mole is.
During a visit of Free French officers in the bunker Potts gets involved and causes a diplomatic incident.
Colonel Witherton sends Potts to his house for few things he will need on a weekend trip, but on the arrival Potts finds the house damaged during the raid and is arrested as a looter.
MI5 receives information that German's plan to assassinate Churchill in the bunker, so the Prime Minister leaves the headquarters and Potts is assigned to fool the German spies by pretending that Churchill is still in the bunker.