The two had now to think of their own safety. Evidently bandits had been tracking them for more than an hour, guided by Doctor Chaleck.
But they soon found that their retreat was cut off by a ring of flames.
"Let us head for the Seine," suggested Fandor, who had discovered a break in the ring of fire at that point. A fresh explosion now took place. From a burst cask a spurt of liquid fire shot up, closing the circle. It had become impossible to pass through in any direction.
They heard the cries of the rabble, the whistles of the officers. In the distance the horns of the fire engines moaned dolefully. The heat was growing unbearable, and the ring enclosing Fandor and Juve narrowed more and more. Suddenly Juve pointed to an enormous empty puncheon that had just rolled beside them.
"Have you ever looped the loop?" he asked. "Hurry up now; in you go; we'll let it roll down the slope of the quay into the river."
In a few moments the cask was rolling at top speed. Juve and Fandor guessed by the crackling of the outer planks and by a sudden rise in the temperature that they were passing through the fire. All at once the great vat reached the level of the river. It plunged into the waves with a dull thud.