An unusual Shadow story. Not just some murders and a who done it. Crooks want to steal two million dollars in uncut diamonds but know The Shadow will stop them so they plan to get him out of the way first. A simple trap with guns does not work so Felix Zubian, a clever tracker is set on him.
He finds out The Shadow is Lamont Cranston, and captures Harry Vincent and Rutledge Mann to help him kill The Shadow but The Shadow saves them, and hides them, with Cranston having to go under cover too and he uses his Henry Arnaud identity, which Zubian also spots.
Of course, Zubian has to die, and in the final fight, we read:
"An arm swept upward from the floor. Behind it came those glowing eyes; but it was not the eyes that stopped Felix Zubian. He was staring into the face of The Shadow - not the disguised features of Lamont Cranston or Henry Arnaud, but the visage of The Shadow himself!
What Zubian saw there; what expression on The Shadow's countenance made even that fiendish villain gasp in horror; no one could ever know. For Felix Zubian knew his last moment of life in that fateful instant.
His trembling finger faltered on the trigger of his gun. The Shadow's unfailing hand did not yield. The last shot that was fired on that night came from The Shadow's automatic."
What horror Zubian saw, in this story written by Gibson himself, we will never know. Certainly not the face of Kent Allard.