We passed through a passage thickly carpeted, and paused before a green baize door.

This door opened noiselessly, and I found myself in the great man's presence.
"It gives me pleasure to welcome the son of my old friend John Arbuthnot," said a clear, and not unfamiliar voice.
I started, looked up, grew red and white, hot and cold, and had not a syllable to utter in reply.
In Doctor Cheron, I recognised-- PYTHIAS!.