The next second, he was thrown twenty yards into the air. He gasped with pain when he struck the ground. "Something pushed me!"
"Are you all right?"
"Yes."
He had fallen on a spot beyond our angle of vision. I started through the passage....
... and struck an invisible solid wall.
My eyes were on the circular opening. A metal panel emerged from a recess on one side and slid across the passage. The room darkened with the absence of starlight.
"What happened?"
"The door to this damned place closed," I explained.
"What?"