Only the murderer could know that!” He shot a glance at O’Brien. “Quick!” The last word was like the sharp lash of a whip.

I was never sure just what happened then. There was a scream as Corole flung herself upon Dr. Hajek. There was another struggle going on somewhere else. Figures blurred in rapid motion—there were outcries—I found myself clutching at Maida—Jim Gainsay’s tall figure flashed before our eyes.

Then O’Leary’s tense voice commanded the situation.

“Right, O’Brien!” he said sharply.

Then the room seemed to clear; things resumed their normal dimensions.

I stared and rubbed my eyes and stared again.

Then my knees weakened under me and I think I screamed.

The handcuffs glittered coldly on Dr. Balman’s wrists.

18. O’Leary Revises His Story

It was fitting that the thing should end as it had begun, in Room 18.