As he did so a streak of light, as if from an electric torch, shone into the room. The old man hurried out on to the landing with wonderful agility, but the light had vanished. He switched on the electric lamp at the head of the stairs. Nowhere was anybody visible.
Glancing quickly in every direction, and with his finger on the trigger of the automatic, he crept cautiously down the stairs. Presently the woman, who had now ventured a little way down the stairs after him, heard him moving in the hall. Soon she heard the spring baize door, which opened on to a passage leading to the kitchen quarters, open with a squeak, then shut with a dull thud.
For a minute she waited, hardly breathing. There could be no doubt that somebody besides themselves must be in the house. Yet how could anybody have entered, seeing that since early in the evening both front and back doors had been securely bolted and locked?
She was trying to summon courage enough to follow her companion, when a sound just behind her made her turn with a cry of alarm.
CHAPTER V.
BEHIND THE DOOR.
A tall, slim man of aristocratic appearance, dressed in a tweed suit and with his hat on, stood at the head of the stairs. He had a walking-stick in his right hand, in his left an extinct electric torch.
“I think you will remember me, Madame Lenoir,” he said quietly.
The woman stared hard at him for a moment, then a look of recognition spread over her face.
“Ha, Milord Froissart!” she exclaimed in a tone of relief. “Ha, but you frightened me, you frighten us both. But how did milord come in? And what is it you want so late at night?”