“I want the ones of the future to know that the Gerns will be here no later than two hundred years from now. And with always the chance that a Gern cruiser in space might pick up the signal at any time before then.”

“I see,” George said. “The sword of Damocles hanging over their heads, to make them remember.”

“You know what would happen to them if they ever forgot. You’re as old as I am⁠—you know what the Gerns did to us.”

“I’m older than you are,” George said. “I was nine when the Gerns left us here. They kept my father and mother and my sister was only three. I tried to keep her warm by holding her but the Hell Fever got her that first night. She was too young to understand why I couldn’t help her more.⁠ ⁠…”

Hatred burned in his eyes at the memory, like some fire that had been banked but had never died. “Yes, I remember the Gerns and what they did. I wouldn’t want it to have to happen to others⁠—the transmitter will be made so that it won’t.”

The guns were melted down, together with other items of iron and steel, to make the castings for the generator. Ceramic pipes were made to carry water from the spring to a waterwheel. The long, slow job of converting the miscellany of electronic devices, many of them broken, into the components of a transmitter proceeded.

It was five years before the transmitter was ready for testing. It was early fall of the year thirty-five then, and the water that gushed from the pipe splashed in cold drops against Humbolt as the waterwheel was set in motion.

The generator began to hum and George observed the output of it and the transmitter as registered by the various meters he had made.

“Weak, but it will reach the Gern monitor station on Athena,” he said. “It’s ready to send⁠—what do you want to say?”

“Make it something short,” he said. “Make it, ‘Ragnarok calling.’ ”