He stepped into the rough wooden contrivance and I followed him gingerly.

“Are we going to break into the flat?” I asked dubiously.

Poirot’s answer was not too reassuring:

“Not precisely today,” he replied.

Pulling on the rope, we descended slowly till we reached the second floor. Poirot uttered an exclamation of satisfaction as he perceived that the wooden door into the scullery was open.

“You observe? Never do they bolt these doors in the daytime. And yet anyone could mount or descend as we have done. At night yes⁠—though not always then⁠—and it is against that that we are going to make provision.”