I never thought of doubting his word. Truth blazed out from his keen grey eyes; his words carried conviction with them.
"I will keep the child," I promised him. "But tell me who you are, and what you have to do with her."
"No matter," he answered swiftly. "I lay this thing upon you, a charge upon your honour. Guard the child. If Delahaye recovers there will be trouble. You must brave it out. You are an Englishman; you are one of a stubborn, honourable race. Do my bidding in this matter, and you shall learn what gratitude can mean."
Once more he listened for a moment intently. Then he continued.
"I am followed by the police," he said. "They may be here at any moment. You can tell them of my visit if it is necessary. My escape is provided for."
"But surely you will tell me something else about the child," I exclaimed. "Tell me at least——"
He held out his hand.
"You are safer to know nothing," he said quickly. "Be faithful to what you have promised, and you will never regret it."
With almost incredible swiftness he disappeared. We all three looked at one another, speechless. Then from outside came the sound of light footsteps, and a laugh as from the throat of a singing bird. The door was thrown open, and Isobel entered.
"Such a funny little man has just gone out!" she exclaimed. "He had a handkerchief tied round his face as though he had been fighting. What lazy people!" she added, looking around. "I expected to find tea ready. Will you please tell me some more about motor-cars, Mr. Arthur?"