The Great War (2014)

Operation Beach Party - Mustard Gas Unleashed (4x28)

:

British Commander Sir Douglas Haig is still convinced of his coming offensive in Flanders. But the Germans now that something is afoot and launch a spoiling attack at the Yser River - the name of the operation is Strandfest or Beach Party. They use blue cross gas for the first time there and two days later also use another new chemical agent which will be known as mustard gas.