He gasped with relief. “You wouldn’t spoil all our days and days of labor, I am sure,” he said. “What was the matter? I don’t understand you.”

You wouldn’t,” was her reply, as she shook herself together and resumed work.

After a while one of the soldiers attached to the laboratory brought in word that the Roies and Formians were attacking the walls, and that “planes” were sailing around in the sky overhead. Cabot gave word to mass his men to defend the laboratory at all costs and went on working.

One by one the tubes were completed and tested.

From time to time Quivven would step into the yard, glance at the sky, and then report back to Myles. The Formian planes were scouting low, but were not dropping bombs. Jud had apparently been right in one thing—that the beasts would not risk injuring the expected prizes of war, namely Arkilu and Quivven.

From time to time runners brought word of the fighting at the outer wall of the city. It would have been an easy matter for the ant-men to bomb the gates, and thus let in their Roy allies, but evidently they were playing safe even there. At last, however, word came that traitors—presumably friends of Tipi—had opened one of the gates, and that the enemy was now within the city.

Still Myles worked steadily on.

Suddenly Quivven returned from one of her scouting trips in the yard with the cry, “One of the air wagons has seen me, and is coming down!”

At that the Radio Man permitted himself to leave his bench for a few moments and go to the door. True, the plane was hovering down, eagerly awaited by a score or so of Cabot’s Vairking soldiers armed with swords, spears and bows. As the Formians came within bowshot they were met with a shower of arrows, most of which, however, glanced harmlessly off the metallic bottom of the fuselage.

The ant-men at once retaliated with a shower of bullets. Two Vairkings dropped to the ground, and the others frantically rushed to cover within the buildings, forcing back Myles and his two companions, as the fugitives crowded through the door.