"Right!" cried Tom. "But how?"
"One of us must stay at the Inn and watch the Marquis to-night, and the other investigate the House on the Dunes. I have already been there and made the acquaintance of the lady, so I had better do that, and you stay here. Do you agree?"
"Yes, of course; though I envy you the chance to be out and doing."
"You will be doing something here. I want you to hide yourself in the hallway near the Marquis's door and watch all night—till dawn anyway. He cannot get out of his room without coming into the hall, and we must know what he does to-night. If the Marquis can spend a sleepless night, we can afford to do so. I don't know what I can do at the House on the Dunes but I shall take the pistol, and you can keep my gun. To-morrow I will get more arms, for I shouldn't be surprised if we needed them. Is everything clear?"
"Perfectly," said Tom. "I'll watch as soon as you are off."
"Good-night, old boy, good luck."
"Good-night," and Dan slipped out of the room and down the dark stairs.
CHAPTER X
MIDNIGHT VIGILS