“Dr. Ringwood speaking.”

As the message came through, his face darkened.

“Very well. I'll be round to see her shortly. The address is 26 Lauderdale Avenue, you say? . . . I'll come as soon as I can.”

He put down the telephone and turned to his guest.

“I've got to go out, Trevor.”

Markfield looked up.

“You said 26 Lauderdale Avenue, didn't you?” he asked. “Talk of the Devil! That's Silverdale's house. Nothing wrong with Yvonne, is there? Sprained her ankle, or what not, by any chance?”

“No. One of the maids turned sick, it seems; and the other maid's a bit worried because all the family are out to-night and she doesn't know what to do with her invalid. I'll have to go. But how I'll find my way in a fog like this, is beyond me. Where is the place?”

“About a couple of miles away.”

“That'll take a bit of finding,” Dr. Ringwood grumbled, as he thought of the fog and his own sketchy knowledge of the local geography.