"Well," replied Blue-Heart after a moment's thought, "I used to see him when he was a lad and Monsieur le Chevalier his father lived in the house yonder, which now belongs to Marshal Cormier. It's because de Livardot comes from these parts, and knows the house so well, that the chiefs are sending him over from England to help us in our work."

"But if he hasn't seen the place since he was a lad——"

"Even so! There are plans of the house and——"

"Hush!" broke in White-Beak peremptorily.

A sudden silence fell upon them. From away down the narrow street had come the weird and mysterious hooting of a screech-owl calling through the night.

Blue-Heart jumped to his feet and in a trice was over the threshold in the other room. He strode across to the window and, leaning out, peered up and down the street.

Before him, about a kilomètre outside the city, the pointed roofs and tall chimneys of Les Acacias peeped above the low houses opposite. It was the residence of Marshal Cormier, Duc de Gisors, and here the Emperor and his suite would sleep on the following night. The wintry moon picked out the metal ornaments of the roofs and the crests of the tall, encircling trees with shimmering lines of silver.

Blue-Heart uttered a comprehensive curse.

"Without de Livardot," he muttered between his teeth, "we shall fail!"

He was about to close the window, thinking that once again his comrades' ears and his own had been deceived, when a solitary pedestrian at the far end of the street arrested his attention—a man walking very slowly, as if he were infinitely weary. He wore an old-fashioned three-cornered hat, and a voluminous mantle was wrapped closely round his shoulders. Blue-Heart waited, breathless, while the pedestrian came leisurely down the street. Presently he paused and, with nose in the air, studied the outside aspect of the houses. Then he put the fingers of both hands to his lips and once more the melancholy call of the screech-owl rang out through the night.