There was the secret message!

"Proceed as planned."

Stuart became suddenly alert.

"By Jove!" he exclaimed. "I must drop down to the Inn, Mayo. I've been expecting some mail — "

"Get it tomorrow," suggested the millionaire.

"No," said Stuart, "I'll have to pick it up now. I can get it before midnight. I'll run down there and see you later."

"How about the car, Fleming?" questioned Mayo.

"Flat tire, sir," said Fleming. "I can fix it — "

"I'll walk down," interposed Stuart. "I'll see you later, Mayo. Don't wait up if I'm a bit late for you."

"I'd go along with you," said Mayo, "but I am a trifle tired. I don't know why — we only came two hundred and forty miles, from New York."