In late 1942, Major Herbert Blondie Hasler designed a raid so dangerous he was forbidden from joining it, then argued his way in anyway. This episode profiles the man and Operation Frankton, an audacious attack on the German-held port of Bordeaux using collapsible canvas kayaks.

We follow the physics of the overloaded canoes, the limpet mines placed below the waterline, the silent short-stroke paddling past enemy warships, and the extraordinary escape over the Pyrenees, alongside the tragic executions carried out under Hitler’s Commando Order.

• Why a canvas Cockle Mk II kayak was chosen to strike 60 miles inland
• How limpet mines and acid-ampoule fuses actually worked
• The loss of half the force before the first night was over
• Hasler’s decision to wait an extra 24 hours in freezing mud
• The astonishing overlap with an unaware SOE mission on the same night