he knew the time element was crucial, that if he won a victory at the palace gates others would come over to his side.

“It is ready,” Kalan told him.

“Then use it,” Meliadus growled. “Use it on the troops manning the walls.”

Kalan nodded and his Serpents trained the weapon. Kalan stepped forward and seized a great lever. He turned his masked face to the lurid skies as if in prayer, then he pulled the lever down.

The machine trembled. Steam rose from it. It rumbled and quivered and roared and from the trumpet grew a gigantic, pulsing green bubble that gave off intense heat. The thing broke loose from the muzzle of the weapon and began to move slowly down towards the walls.

Fascinated, Meliadus watched it drift, watched it reach the wall and settle upon a score of warriors. With satisfaction he heard their screams break off as they writhed in the hot, green stuff and then vanished completely. The ball of green heat began to roll along the wall, gobbling its human prey until suddenly it burst and green liquid boiled down the sides of the wall in viscous streamers.

“It has broken. It does not work!” Meliadus yelled in rage.

“Patience, Meliadus,” Kalan shouted. His men were repositioning the weapon by a few degrees. “Watch!” Again he pulled down the lever, again the machine shook and hissed and slowly another gigantic green bubble formed at its snout. The bubble drifted to the wall, rolled over another group of men and rolled again. This one rolled longer until there was hardly a warrior left on the wall when it eventually burst.

“Now we send them over the wall,” Kalan chuckled and pulled the lever once more. This time he did not wait. As one boiling green bubble left the muzzle, he would bring another into being until at least a score of the things had drifted over the walls and into the courtyard beyond. He worked furiously, totally absorbed in

his work, as the machine shuddered and hissed and threw off almost unbearable heat.

“That mixture will corrode anything!” Kalan yelled excitedly. “Anything!” He paused for a moment to point. “Look what it is doing to the walls!”

Sure enough the viscous stuff was eating its way into the stone. Huge pieces of highly decorated rock fell into the street below, forcing the attackers to back off. The mixture ate through the stone as boiling oil might eat through ice, leaving huge jagged gaps in the defences.

“But how will our men get through?” Meliadus complained. “That stuff will not care what it eats!”