They found the other entrance behind a stand of bitter thorn.
It was not a secret door. The station’s older workers knew it as the lower washout, and Edda had brought a key. But a roof fall long before her time had cut it off from the main inspection gallery. Nobody had used it for more than storage in years. A pair of broken cleaning poles lay under the thorn, their wood soft enough for Iven’s thumb to leave a mark.
Kesh crouched beside the opening. The three-point tracks crossed in both directions.
“Whatever’s inside can come out here,” she said.
“Then why the locked upper gate?” Kardo asked.
“To keep people out of the tank,” Edda said. “Not animals.”
She opened the washout cover. Cold, damp air moved past Iven’s face. The passage beneath was high enough to crawl through, with a low channel along one side carrying a trickle of clear water. He could hear the stone clicking again, closer now.
Thessa tested the air at three heights. The lowest sample made her frown.
