From outside, came the sound of successive, powerful blasts. The black ship was bringing its heavy guns into action, was bombarding the city.
Zurk caught two of the creatures as a great cat would catch mice. Their gibbering death-cries filled his ears with pleasure as he smashed their heads together and flung their lifeless bodies against the wall.
"The disintegrator!" he shouted to Bob. "Knock that ship out of the sky! This will be a fight they will remember!"
His steel fist crashed into the evil brain of another.
Then came a roaring bolt of destruction more powerful than all the others. It struck the corner of the attic, quaked the building to its foundations and sent one wall of the laboratory swirling away in a burst of flying debris.
Two of the trapped creatures sprang out of the opening, screaming. Zuldi would have followed had not Zurk clutched him up in his huge hands. Slowly, the man of steel twisted the evil creature's head about in a complete circle. Then he raised the lifeless body high into the air and cast it down into the dust of the street below.
His great steel hand shot out and seized Zuldi's scaly neck.