It was not a free, frank smile.

To tell the truth, he was a bit annoyed, for besides the two youths there was Mole, and the attendant darkeys with them, Tinker and Bogey.

Lenoir was a cautious man, and he did not care to run risks.

"Are they friends and confidants of yours?" he asked, rather pointedly.

It was an odd speech to make, but as he smiled slightly, they took it for a sort of joke.

"Oh, yes, they are confidential friends," returned Harry Girdwood, smiling.

"Very good, let us begin our look round. We will walk along the quays if you like, and thence past the Hotel de Ville. I shall show you several objects of undoubted interest," said Lenoir, significantly.

He led the way on.

Jack fell back a few paces, walking on with Harry Girdwood.

"He's a very odd fellow," whispered the latter.

"Very."

Lenoir led them over the town before he ventured to approach the Caveaux.

"I have a little museum not far away," he said.

"I am afraid we shall be intruding," began Jack.

"Not a bit," protested Lenoir.

The snuggery in question was situated at some little distance from the town, and away from the main road.

The cottage was only a one-story building.

"His museum is not very extensive," whispered Harry Girdwood to his companion, "if it is that cottage."

Lenoir was remarkably quick-eared.

"My museum is cunningly arranged," he said to Jack, looking over his shoulder as he walked on; "you don't get all over it at once. Here we are."

They had reached the threshold, and opening the door, he led the way in.

It was a neat little cottage interior, with nothing about it to attract attention.

Pa.s.sing through the first room, Lenoir conducted them to a sort of out-house beyond.

Here they came upon the first surprise.

He opened a door which apparently shut in a cupboard, and this, to their intense astonishment, revealed a flight of stone steps which seemingly led into the very bowels of the earth.

"Hallo!" exclaimed Jack; "why, what's this?"

"I thought I should astonish you, now," said Lenoir, with his same calm smile.

"What is this place?"

"There is a whole series of caves below these, apparently natural formations. The only way I can account for them myself is that at some time or other some experimental mining operations have gone on there.

Would you like to go down and see the place?"

"With pleasure," returned Jack, eagerly.

"Allow me to lead the way."

When they had descended a few steps, Jack half repented.

This man was a stranger to them, and he had brought them to a very wild and out-of-the-way place.

Had he any evil purpose in bringing them there?

Jack stood wavering for a few seconds--no more.

"We are four," he said to himself, "four without counting Mr. Mole; they must be a pretty tough lot to frighten us much, after all said and done."

So saying down he went.

The others followed close behind him.

At the base of the flight of steps they found themselves in a s.p.a.cious vault that was unpleasantly dark.

"Allow me to lead the way now," said Lenoir, pa.s.sing on. "Follow me closely; there is no fear of stumbling, there is nothing in the way."

So saying, he conducted them through this opening, which, by the way, was so low that they had to stoop in pa.s.sing under, and found themselves now in a narrow cave, which reminded young Jack forcibly of the dungeon and its approach of Sir Walter Raleigh, in the Tower of London.

"What do you think of this place?" demanded the guide.

"A very curious sight," was the reply. "You put all this s.p.a.ce to no use?"

"Pardon me," said Lenoir; "I practise my favorite hobby here."

"Here!"

"Yes--or rather in the next cellar beyond."

"And what may be that favourite hobby?"

"Medalling," was Lenoir's reply.

And again he shot at his questioners one of those peculiar glances which had so astonished them before.