The hall held some rubble, as well as the resinous plaster debris DD had scraped from the last hastily written hieroglyphics. Louis worked with his bare hands, piling iron bars and rubble across the threshold, trying to build up a barrier. The hulking black robots would smash through it in seconds.

Outside, they heard the thump and skitter as Sirix, Ilkot, and Dekyk landed inside the overhang. The robots began to make their way through the corridors of the abandoned city, moving with a ponderous heaviness, their machine bodies cumbersome but relentless.

“Damn, I wish the Klikiss used doors.” Margaret looked in dismay at the open hall, the passage leading toward the stone-window chamber. The power source still hummed in the portal-wall machinery, though neither Louis nor his wife understood yet how the device functioned.

DD dutifully added to the meager blockade using boxes of supplies, small pieces of equipment. Louis shook his head in disbelief at their pathetic effort. The Friendly compy looked back at them. “Is there anything else I can do, Louis? I would be glad to assist in any way you deem appropriate.”

Louis frowned. “Well, I don’t suppose you have any defensive programming? Can we change you into a combat robot?”

“Perhaps if there were a programming module on hand,” DD said. “However, I am not certain how effective I could be, since I have no built-in weapons or armor.”

“Not to mention the fact that you’re about a third the size of a Klikiss robot.”

Margaret looked over her shoulder. “You can’t harm humans, is that correct, DD?”

“I cannot harm humans, Margaret.”

“And I presume a necessary corollary is that you cannot allow humans to come to harm?”

“I will do everything in my power to prevent that, Margaret.” Louis looked sadly at the silvery compy, knowing he was about to give DD a suicide order. “Then you’ve got to stand against the Klikiss robots, DD. Stay in the corridor and prevent them from reaching us.” He swallowed hard. “Delay them… however you can.”

DD accepted his orders bravely and stood in the center of the narrow, rock-walled passageway. The silver-skinned compy looked laughably weak compared with the enormous Klikiss robots. Louis thought of a heroic little guard dog barking furiously at a brutal intruder.

Margaret grabbed her husband’s arm and pulled him deeper into the chamber. “Louis, I need you. We’ve got only a few minutes to figure out this transportation system.” He was amazed she would suggest such an option. She saw that his doubt reflected her own, but she said, “It’s the only nonzero chance we have, old man.”

“All right.” He hurried over to the machinery. “This is why I wanted a career in xeno-archaeology, to see strange new places. Usually, though, I have some inkling of where I’m going.”