Mr Burrows, however, was all philosophy and chattiness.

We left them, as I say, together, and sank deeper and deeper into the under-world of that mysterious house, which, perhaps, appeared to us somewhat more Tartarean than it really was, owing to our knowledge of its semi-criminal mystery and of the human secret locked below.
The basement floor had several doors, as is usual in such a house; doors that would naturally lead to the kitchen, the scullery, the pantry, the servants' hall, and so on.

Rupert flung open all the doors with indescribable rapidity.

Four out of the five opened on entirely empty apartments.

The fifth was locked.