"The lost race? That they lived on Ganymede thousands of years ago, and had the greatest science ever known to the System. That they died, nobody knows how, and the secrets of their civilization were lost. Chahnn's only one of their ruined cities. There've been a dozen others found. And full of gadgets and robots that nobody knows how to work. There was a central power-source, but Earthmen have never figured out how it worked or what fuel was used. The inscriptions found in the cities didn't tell anything." "Fair enough," Brown nodded. "Except you forgot one thing. You know the Ancient Tongue. You speak it." Garth chewed his lip. "So what?" "Where did you learn it?" "I don't know. In the Black Forest, I suppose. I don't remember." The girl made an impatient gesture. She quieted as Brown glanced at her. "From the Zarno, Garth?" "_I don't know!_ There's no proof the Zarno even exist!" "If you've gone far enough into the Black Forest--" Garth said angrily, "Remember what I told you about the Noctoli? The effect of the pollen? When I got back to Oreport here I had amnesia. I--" He hesitated. "I don't remember. I never did remember what happened in the Black Forest." "Um-m." Brown rubbed his cheek again. "A lost race of savages no outsiders have ever seen--a race speaking the tongue of the Ancients. How could they live around those Noctoli flowers of yours?" "Natural immunity," Garth said. "Built up over a period of generations. I didn't have that--then." * * * * * The girl leaned forward, ignoring Brown. "Mr. Garth," she said swiftly, "I think I'd better explain a bit more. Shut up, Carver!" She frowned at Brown. "There've been too many mysteries. Here's the set-up. I've got half of a--a map. It shows the location of something in the Black Forest that's immensely valuable--the greatest treasure the System's ever known. I don't know what it is. The original inscription, in the Ancient's language, is cryptic as the devil. But the Ancients thought this treasure important enough to be worth hiding in the Black Forest. They set the Zarno to guard it. See?" Garth grunted. "So what?" "Well--I'm Paula Trent, archaeologist. Not that it matters. For months Carver and I have been waiting our chance to fit out an expedition and come on here. We didn't have the money, at first, and when we did get it, the government refused us permission. We had no proof, they said, and the Black Forest is impenetrable. So we waited. A month ago we got wind of a research ship, the _Hunter_, coming on here to investigate Chahnn. The same old stuff--digging around in the ruins, trying to find out what made the machines and robots tick, trying to make sense out of the inscriptions. Trying to find a cure for the Silver Plague." Garth said, "No cure's been found yet, then."