In answer the Hindu turned on the light. He pointed it to the blank wall, then above. On the ceiling, Duncan saw a small button. He doubted that he would have seen it had it not been indicated for him.
"I could reach to there," explained Abdul. "I know that button means something. My eyes are good, sahib. When I see that, I know it has some use. So I press. Down comes the little room — with you, burra sahib."
The Hindu turned off the light.
"Well, Abdul," said Duncan, in the darkness, "you have saved my life. Above here is a room — a room in which I sat, not suspecting that Isaac Coffran was my enemy. The room gradually filled with a poisonous vapor. I pressed a button up there, but it served no purpose, for the elevator was up.
"I can understand the use for the elevator. The old man would have placed my body in it. From here, in the basement, he would have brought down the elevator. An easy, simple way to remove a murdered person."
He rose and groped toward the wall ahead.
"Turn on the light, Abdul," he said.
The Hindu complied. At that instant a cry came from Bruce Duncan. The floor caved beneath him. He dropped downward, but his course was halted by the alert Hindu. The man had dropped the light, and his hands had caught Duncan underneath the arms, just as he was disappearing into the depths below.
* * *
As soon as Abdul had drawn his master to safety the opening in the floor swung upward. It was a hinged device by the wall below the elevator. Its springs made it close so tightly that even under the inspection of the flashlight the cracks seemed hardly noticeable.