After a moment's hesitation, she shrugged her shoulders and turned the key.
It rasped, proved stubborn, but at last came home with a click.

Then she turned to the window.

It was open about three inches at the bottom.

She closed it tight, and fastened it, then stood for a moment in the middle of the room looking at both door and window.
She was conscious of a sense of suffocation.

Never in her life had she slept with door or window or tentflap entirely closed.