All at once I had it! Red spot fever. Heat fever from the infra-red rays of Jupiter's great spot. Someone had constructed this lens to concentrate and amplify the power of those rays. The internal clockwork served a double purpose. It opened a shutter, and it rotated the lens slowly so that it played for a time on each of the sleeping men.
I slid the metal button in my pocket and left the barracks at a run. Back in the visiscreen room, I snapped to the operator:
"Turn it on!"
The kite car swam into view in the screen above the instrument panel. I stared with open eyes. Jimmy Baker no longer was in the car, nor was Xartal, the Martian. Grannie Annie was there, but seated at the controls was Antlers Park, the manager of Interstellar Voice.
Ezra Karn jabbed my elbow. "Grannie's coming back. I thought she'd be getting sick of this blamed moon."
It didn't make sense. In all the years I'd known Annabella C. Flowers, never yet had I seen her desert a case until she had woven the clues and facts to a logical conclusion.
"Ezra," I said, "we're going to drive out and meet them. There's something screwy here."
Ten minutes later in another kite car we were driving at a fast clip through the powdery sands of the Baldric. And before long we saw another car approaching.
It was Grannie. As the car drew up alongside I saw her sitting in her prim way next to Antlers Park. Park said: