THE way she acted out the turning of the doorknob convinced me. She held one hand out flat to represent the door and curled up the fingers of the other so that they grasped its rounded doorknob.

Then came the struggle. She showed how, with her petrified daughter screaming in her ear, she’d used all her strength to turn the knob anticlockwise, desperate to keep the door shut.

But whatever was on the other side was just as strong. It matched her effort. Then it got stronger, slowly overwhelming her, forcing her fingers to turn clockwise against themselves until she was waiting for the little click that would mean the latch was out of the catch and they were at the mercy of whatever it was – “a thing, a thing”, her daughter hysterically shrieked.

It’s a doorknob – dark resin, in the style of their late-1920s’ house – I have held as I’ve often been at their house for dinner. As the wine flowed, I’ve heard how the house, on the edge of Darlington, was built by an undertaker, and how they demolished his peculiar patio, covered in initials and decorated with items such as shells pushed into the concrete.

“We got enough glass eyeballs from it to fill two shoeboxes,” she said.

I’ve also heard how when one of the girls was small she’d cry out: “Can you see the faces in the wall, mummy?”

When she went to comfort, she’d smell an old man behind her. One night, she got quite stern with him. “This is my house now,” she said, and never smelled him again.

But this doorknob story was new, and quite physical. It happened the week before Christmas.

Her husband was away; her younger daughter was at a sleepover. She was alone with her mid-teens daughter watching A Good Year, a gentle rom-com set in Provence.

Her daughter nipped out of the front room, down the hall, across the utility room, past the back door, towards the toilet… “Suddenly, I heard this piercing panicstricken scream and she came hurtling back into the front room, ashen, shouting ‘There’s something in the utility room’,” said her mother.

Had the cat brought in a scuttly mouse?

“It’s a thing, a thing,” the girl screamed.

The mother remembered the back door was unlocked. She slammed the front room door shut, jemmying her foot against it, grabbing the doorknob while realising that the window was painted up and she was barricading them into a prison with no way out.

And then the handle turned against her.

“It’s not a man, mummy,” screamed the girl. “It’s white and tall and it came from behind me and stood beside me.”

“At that moment,” said the mother, “I felt considerably less scared. A ghost might frighten the living daylights out of her, but at least it wouldn’t rape her.”

And at that moment, the knob stopped turning. The little click never came.

The moment passed. If only to assuage her daughter, she still had to open the door.

When she did, there was nothing there. Not in the hall, on the stairs, or in the utility room. No rapist, ghoul or sheet drying spookily on the airer – not even a scuttly mouse.

Except that the utility room, the warmest in the house as it’s first on the central heating loop, was so cold she could see her breath.

Except that when her husband returned next day unaware of the drama, he found the cat growling a most uncatlike noise at the utility room door.

Except that the knob really had turned in her hand.