Published in The Victor #625, Feb 10, 1973.
It is March, 1918. In Flanders the British forces are being drilled by a huge German offensive. The Black Rider uses a special underwater feature to cross the Yser Canal unnoticed. The mission is to disguise his vehicle as a German one to help an agent pose as a German general to get into their local HQ to confuse their plans. Things are not all what they seem.