But the Frenchman shrank back.

"Come, there is no danger," smiled T. B.

Reluctantly the engineer accompanied the detective and the editor from the building. A yellow fog lay like a damp cloth over London, and the Thames Embankment was almost deserted.

"Do you think he followed you here?" asked T. B.

"I am sure." The Frenchman looked from left to right in an agony of apprehension. "He killed Hyatt and he killed Moss—of that I am certain—and now——"

A motor-car loomed suddenly through the fog, coming from the direction of Northumberland Avenue, and overtook them. A man leant out of the window as the car swept abreast. His face was masked and his actions were deliberate.

"Look out!" cried the editor and clutched the Frenchman's arm.

The pistol that was levelled from the window of the car cracked twice and T. B. felt the wind of the bullets as they passed his head.

Then the car disappeared into the mist, leaving behind three men, one half fainting with terror, one immensely pleased with the novel sensation—our editor, you may be sure—and one using language unbecoming to an Assistant-Commissioner of Police.