The Clones of Mawcett (A Galaxy Unknown Series #3)

While digging through the ruins of a long dead civilization on the planet Mawcett, a team of Terran and Nordakian archeologists find an underground tunnel leading to a door in such extraordinary condition that it could have been fabricated as recently as that morning. They labor throughout the day, using every modern device available to them, but are unable to gain entry.

Then, in the early hours of the new day, seemingly in response to the screams of a frustrated, over-tired scientist, the door slides noiselessly open. Upon passing through the entranceway, the archeologists are stunned to find an elaborate complex in pristine condition. Summoning the courage to venture further, they enter a large circular chamber lined with strange electronic equipment, and immediately become engrossed in examining strange symbols etched into the floor near the center of the room. Suddenly, they're bathed in a strange light that paralyzes them where they stand. They watch in frozen terror as a clear, circular wall rises up around them. When the enclosed area begins to fill with a dense ocher gas smelling of persimmons, the dig site laborers, who had witnessed the activity from the periphery, run screaming for the entrance.