"Ten, fifteen, eighteen, twenty, if need be."

"It will have to be done. Do not miss a word of what I am about to tell you. You will go to the woods of Saint-Aubin."

"Near Lamballe?"

"Yes. On the edge of a ravine between Saint-Rieul and Plédéliac there is a large chestnut-tree. You will stop there. No one will be in sight."

"But a man will be there nevertheless. On that I can depend."

"You will give the call. Do you know it?"

Halmalo puffed out his cheeks, turned towards the sea, and there rang the "to-whit-to-hoo" of the owl.

One would have supposed it came from the depths of a forest, so owl-like and sinister was the sound.

"Good!" said the old man. "You have it."

He extended to Halmalo the green silk knot.