The blow missed her head by the fraction of an inch and fell on her shoulder, sending a paralysing thrust of pain down to her fingertips and across her breast.

And that’s my right arm gone! Now she is stronger than I am. She’ll overmaster me and open the door. She’ll be raped and I shall be killed!

The force with which she had struck had disturbed Ethel’s balance, and as she teetered, stupidly, motivelessly, Miss Mayfield shot out her left hand, grabbed the torch and struck – against Ethel’s fawn-coloured head – the first violent blow she had ever dealt anybody in her life. Ethel crumpled down into a little heap on the floor.

Oh, God, I’ve killed her. I never meant to hit so hard. What got into me? I must be mad. God, don’t let her be dead. It would be such a triumph for Them!

That prayer, anyway, was answered. For when she had set down the torch and redirected the beam, she could see that Ethel was breathing as steadily as a sleeper; and her pulse, though a little slow, was strong and even.

She had hardly satisfied herself that Ethel was not dead, not even bleeding, when Miss Thorby cried:

‘Ethel!’ In some obscure fashion she must have become aware of a break in the contact. ‘Ethel! Do you hear me? Answer me!’

Miss Mayfield looked at Ethel, half expecting her to rise and make an automatic response, but Ethel lay as though asleep.

When Miss Thorby next spoke, there was a hint of hysteria in her voice. ‘Answer me, answer me. Are you afraid of her? She can’t hurt you if you do what I say. Ethel, Ethel, Ethel!’

The high-pitched, almost yelping cry seemed to cut into the little circular room, to rebound from its walls and then die away. There was a moment’s silence.

Then, still sharply but with more control, Miss Thorby called, ‘Miss Mayfield!’

Well, there was nothing uncanny about that. Miss Thorby might have seen her; she would certainly guess.

‘I don’t care whether you answer me or not; I just want to make certain that you can hear me.’

‘I hear you perfectly well,’ Miss Mayfield said.

‘We know you’re mad. Deep down, you must know yourself that you’re mad. Come out now and give yourself up and I promise you shall be treated kindly. If you don’t, it’ll be the public lunatic asylum. Do you know what that will mean?’