"So you see, Madame, why we are anxious for any information we can possibly get."
"But surely her maid—"
"The maid has disappeared."
"Oh!" Katherine paused to assemble her thoughts.
"Since the conductor had seen you talking with her in her compartment, he quite naturally reported the fact to the police, and that is why, Madame, we have detained you, in the hope of gaining some information."
"I am very sorry," said Katherine; "I don't even know her name."
"Her name is Kettering. That we know from her passport and from the labels on her luggage. If we—"
There was a knock on the compartment door. M. Caux frowned. He opened it about six inches.
"What is the matter?" he said peremptorily. "I cannot be disturbed."
The egg-shaped head of Katherine's dinner acquaintance showed itself in the aperture. On his face was a beaming smile.