"Yet you must discover what it all means to-night or not at all," she whispered. "The dear Andrea has intimated to me most delicately that another escort would be more acceptable if I should honour him again."

"That helps," he murmured. "See, our last guest arrives. Ah!"

A tall, spare-looking man was just being announced. They heard his name as Andrea presented him to a companion:

"Colonel Mayson!"

Mademoiselle Celaire saw a gleam in her companion's eyes.

"It is coming—the idea?" she whispered.

"Very vaguely," he admitted.

"Who is this Colonel Mayson?"

"Our only military aeronaut," Peter replied.

She raised her eyebrows.