The Enigma machine is to be smuggled to England in the midget submarine. Renandeacute; is told to put the machine into a wine barrel and drop it into the sewer. At a certain time, everyone in Nouvion will flush their toilet and the resulting surge of water will send the wine barrel along the sewer to the submarine.
The British lay on an air raid as a diversion, but they manage to bomb the pumping station by mistake, so there's no water to flush the toilets with. It's discovered that Monsieur Le Clerc has put the wrong box in the wine barrel. The Enigma machine is still hidden in the cafandeacute;.

'Allo 'Allo! Season 5 Episodes...

• s05e01 - Desperate Doings in the Dungeon
• s05e02 - The Camera in the Potato
• s05e03 - Criminal Developments
• s05e04 - Return of the Paintings
• s05e05 - Enter Denise
• s05e06 - A Marriage of Inconvenience
• s05e07 - No Hiding Place
• s05e08 - The Long-Distance Duck
• s05e09 - The Generals' Conference
• s05e10 - Michelle's Secret Love
• s05e11 - The British Invasion
• s05e12 - Parade of Prams
• s05e13 - The Bank Job
• s05e14 - The Reluctant Millionaires
• s05e15 - Forged Francs & Fishsellers
• s05e16 - The Exploding Bedpan
• s05e17 - Feathers
• s05e18 - Leclerc Against the Wall
• s05e19 - Christmas Puddings
• s05e20 - Mines Away!
• s05e21 - All Aboard
• s05e22 - The Geneva Express
• s05e23 - Enigma
• s05e24 - Renewing the Vows
• s05e25 - The Big Flush
• s05e26 - Enigma's End

'Allo 'Allo! Show Summary

In this spoof of World War II, Renandeacute; Artois runs a cafandeacute; in German-occupied France. He always seems to have his hands full: He's having affairs with most of his waitresses, he's keeping his wife happy, he's trying to please the German soldiers who frequent his cafandeacute;, and he's running a major underground operation for the Resistance.