He wondered whether Thalassa and his wife had left the place.
Then he noticed that the door was merely closed and not shut.

He lifted the heavy iron knocker, and knocked loudly.

The repeated knocking sent the door flying open, and Barrant found himself looking into an empty hall.
Half-way down a pair of curtains stirred slightly and parted suddenly, revealing a narrower passage which led to the door of the kitchen.

The curtains streamed horizontally, twisting and coiling like snakes.

Barrant stepped quickly inside and closed the door.