The mysterious radio signals from Germany which could guide enemy night bombers to a pin-point target anywhere in the British Isles could have proved disastrous for the almost non-existent British defences. Professor R.V. Jones of the RAF Scientific intelligence recounts how the "Beams" were first discovered and then countered...with crucial timeliness.

The story of wartime radar, and the struggle to keep one step ahead of the enemy, is one of a deadly battle fought in the laboratory and the night skies of Germany; a desperate, silent contest played out at what was then the very frontier of scientific progress. Included in this absorbing account of the radar war are contributions from many of the British and German participants.

In the early hours of 13 June 1944, a small German aircraft crashed and exploded in Bethnal Green, killing six civilians. Rescue workers could find no German Crew. That was because there was none. The V1 had arrived, and with it a terrifying new era in warfare.

Although the magnetic mine had been invented by the British in 1917, interest had languished in Britain between the wars, and it was the Germans who were to develop the device to new levels of deadly effectiveness. This is the story of how two navel officers calmly and fearlessly dismantled the first German magnetic mine on a sand bar off Shoeburyness, and reveals how its various successors were discovered and countered by the British.

This is the story of weapons which might have been; weapons as diverse as the incredible Giant Panjandrum and the equally extraordinary Gigant, a glider almost as large as a Jumbo jet.

There can be no doubt that the best kept secret war was the penetration by British Intelligence of the German codes known as Enigma. To this day the whole story has yet to be told. However, this account, recounted by some of the men and woman involved and chiefly shot on location in the actual secret wartime venues, reveals just about all that is known.

A detailed look into history, the technical developments and tactics used by both Allied and Axis sides during this long and difficult campaign, featuring such innovations as Asdic, Type 271 radar, Wolfpacks, Cam Fighters, Hedgehog, Huff-Duff, US Blimps, ASV radar, the Leigh light, Metox, Naval H2S radar, Schnorkels and Escort carriers. Contributions from Donald Macintyre, Patrick Beesly, Carl Emmermann, Humphrey de Verd Leigh, Hans Meckel and Bernard Lovell. Although included in video versions of The Secret War as a seventh episode, this last programme was not made as part of the actual series and was aired separately from The Secret War when first shown. The completely different introduction; title music and credits betrays this (particularly as 'The Secret War' does not appear in the title sequence anywhere, unlike the other 6 episodes).