When it got to about two metres high, the wall advanced to the rim of the flaming trench. Its surface writhed in the heat like an angry python. Scorched by the blaze, it began to smoulder and the acrid smell of roast ant filled the air. Charred bodies tumbled into the smelter below, lending the flames a ghostly green hue. But new layers of ants continually filled in for their fallen comrades, leaving the wall standing firm on the edge of the hellish ditch.

Black spheres now began hurtling over the top of the wall. Some were snatched by the fires but most had enough momentum to propel themselves across the moat to the other side. As they passed through the inferno, the spheres’ outer layers sizzled and fried, but the ants held tight to each other, forming a scorched shell that protected their comrades inside. Within mere moments, more than a thousand balls had reached the opposite bank of the trench. Their burnt shells split open and the spheres dispersed into vast throngs of ants that surged up the steps of the signal station.

At this point, the dinosaur guards lost it. Despite the lieutenant’s attempts to stop them, they raced out the door and around to the rear of the building, galloping at full tilt along the only path not yet completely awash with ants. The ants streamed into the ground floor of the signal station, then up the stairs to the control room. Other divisions scaled the exterior walls, spilling in through the windows, painting the lower half of the building black.

Six dinosaurs remained in the control room: the lieutenant, the engineer, the technician and the three operators. They watched horror-stricken as the ants poured in through every crack and crevice. It was as though the building had been submerged in a sea of ants, its black waters leaking in through every orifice. The view out the window was no different. As far as the eye could see, the ground was a roiling ocean of ants, the signal station a lonely island stranded amid it.

In no time at all, the entire control-room floor was carpeted with ants, save for a circle around the central console in which stood the six dinosaurs.

The dinosaur engineer hastily took out his translation device. He heard a voice as soon as he switched it on.

‘I am the supreme consul of the Ant Federation. We do not have the time to explain everything to you in detail. All you need to know is that if this signal station does not transmit its signal in the next ten minutes, Earth will be destroyed.’

The engineer peered confusedly at the dark mass of ants encircling him. Then he consulted the translator’s direction indicator. It pointed him towards three ants standing on top of the central console. The voice that had just spoken belonged to one of them. He shook his head at the trio. ‘The transmitter is broken.’