We turned the corner and walked along a deserted and unlit, Rue du Cloître-Notre-Dame. The almost century old Notre-Dame towered above us on the right, and ancient apartment buildings flanked us on the left.

He turned towards one of these apartment blocks. We entered a glass and steel door and stepped into a dark, unmanned foyer. We got into a brightly lit, yellow, wood-paneled lift, barely large enough for the two of us. Neither said a word as we ascended. We reached, what seemed to be the top floor and stepped into the corridor. We arrived at a white door. Patrick unlocked it and it swung open quietly.