"Cat stairs," said Mlle. Fouchette.
"And the cats have used it a good deal of late, I should judge," he observed, carefully examining the entrance in the glare of the lamp.
"Leads to the roof, probably," she muttered.
"Probably. Let us mount."
"Oh, yes, let us follow the trail."
The instinct of the woman and the spy was now strong within her.
The "cat stairs" were closed at the top by a heavy oaken trap securely fastened within by two iron hooks.
"It is astonishing!" he said.
"What?"
"These fastenings, keys, bolts, bars, are all on this side."