“I know,” said Ganimard. “The Porte d’Aval hides the whole of the coast of Étretat and Yport. But look, over there, in the offing, that black line, level with the water—”
“Well?”
“That’s our fleet of war, Torpedo-boat No. 25. With her there, Lupin is welcome to break loose—if he wants to study the landscape at the bottom of the sea.”
A baluster marked the entrance to the staircase, near the fissure. They started on their way down. From time to time, a little window pierced the wall of the cliff; and, each time, they caught sight of the Needle, whose mass seemed to them to grow more and more colossal.
A little before reaching high-water level, the windows ceased and all was dark.
Isidore counted the steps aloud. At the three hundred and fifty-eight, they emerged into a wider passage, which was barred by another iron door strengthened with slabs and nails.
“We know all about this,” said Beautrelet. “The document gives us 357 and a triangle dotted on the right. We have only to repeat the performance.”
The second door obeyed like the first. A long, a very long tunnel appeared, lit up at intervals by the gleam of a lantern swung from the vault. The walls oozed moisture and drops of water fell to the ground, so that, to make walking easier a regular pavement of planks had been laid from end to end.
“We are passing under the sea,” said Beautrelet. “Are you coming, Ganimard?”
Without replying, the inspector ventured into the tunnel, followed the wooden foot-plank and stopped before a lantern, which he took down.