Paula Grey "witnesses" the murder of Norbert Engel, key German statesman, in Vienna. A veiled woman entered and left the building. Is she a member of the shadowy, sinister Sisterhood?

          One by one, the elite strong men in a leaderless Europe are assassinated. Tweed suspects a prelude to the takeover of the Continent by a power from the East – but not Russia. What part is played by Captain Wellesley Carrington, flamboyant landowner in Dorset, by his neighbour Amos Lodge, eccentric strategist? By Tina Langley, Carrington’s glamorous "friend"?

          Tension rises as Tweed, Paula and Bob Newman fly to Zurich, where a fresh assassination takes place. Again a veiled woman was seen leaving the murder location. Tweed’s desperate pursuit leads to the vast plain east of Vienna, to a strange village – reminding Tweed of a weird village in Dorset. Attempts are launched to kill Tweed.

          Paula infiltrates The Sisterhood, becomes a target. Newman meets the wily redhead Simone Carnot. Is Geneva the real key? The action swings back to Geneva – across the frontier into France. The ultimate horrendous clash comes on the night the enemy plans to overwhelm the West.