“Your best bet is to see Captain Vandervelde. If anybody can fix it, he’s the boy. You’ll find him in the Passage de Haynau, Rue Croix Nivert.”

“What number?”

“There is no number.”

I thanked him, or perhaps I forgot to, and returned to my taxi.

“Passage de Haynau in Rue Croix Nivert,” I said.

“ Q’numéro? ”

“There ain’t none.”

“Come on,” demanded the driver.

“I told you there was no number. We’ll just have to keep looking till we find it.”