“There is a watch which can be put upon them, needing no men. A trick I know. Let us get to Magnis.” He began to run, the point of his sheathed sword clinking now and again against the stone walls as he rounded the turns in the keep corridors.

Basins were lined up on a table, of all sizes and several shapes, but they were uniformly of copper and the balls Koris was carefully apportioning, one to a bowl, were also of metal. One of the bowl and ball combination, installed in the portion of wall overhanging an underground way, would betray any attempt to force the door far below by the oscillation of ball within basin.

Earth was safeguarded as best they could. Which left — the air. Was it because he was familiar with air warfare that Simon found himself listening, watching, at the cost of a crick in the neck, the murk encasing the towers of the port? Yet a civilization which depended upon the relatively primitive dart guns, the sword, the shield, and a mailed body for offense and defence — no matter what subtle tricks of the mind they called in bolstering aids — could not produce airborne attack as well.

Thanks to Koris’ device of the bowls they had a few moments of warning when the Kolder thrust came. But from all five points where the bowls had been placed that alarm arose at nearly the same instant. The halls leading to each doorway had been stuffed during frenzied hours of labor with all the burnable stuff in the warehouses of the port. Mats of sheep wool and cowhair soaked in oil and tar, which the shipwrights used for the calking, were woven in around torn bales of fine fabrics, bags of dried grain and seeds, and oil and wine poured in rivulets to soak into these giant plugs.

When the bowls warned, torches were applied and other portals closed, sealing off from the central core those flame-filled ways.

“Let them run their cold dog noses into that!” Magnis Osberic thumped his war ax exultingly on the table in the central hall of the main keep. For the first time since the fog had imprisoned his domain the Master Trader appeared to lose his air of harassment. As a seafarer he hated and feared fog, be it born of nature or the meddling of powers. With a chance for direct action, he was all force and drive again.

“Ahhhhhh!” Across the hubbub in the hall that scream cut like a sword slice. Torture of body was not all of it, for only some supreme fear could have torn it from a human throat.

Magnis, his bull’s head lowering as if he would charge the enemy, Koris, sword ready, a little crouched so that his dwarfish body gathered strength from the earth, the rest of the men in that chamber were frozen for a long second.