‘And this, my friend, is a real treasure.’

He handed me an oblong rosewood box inlaid with mother of pearl.

‘It’s a nice enough box,’ I said, not particularly wanting to be talked into overpaying for something I did not really desire. That has happened once too often and i honestly did try not to come in to Mosse’s Antiques and Vintage, not more than once a month, anyway.

‘Not the box,’ said Mosse with an impatient wave of the hand.

I opened the box and inside there lay a nice, but not rare, pearl-handled dip pen with a gold nib, old ink still crusted at its tip.

‘Erm, well, it’s a nice enough pen—‘

‘That, my friend, is the pen of Aesop Allen.’

My stomach gave a little twist, but he might as well have been trying to sell me a yeti tooth.

‘Oh yes?’ I said with as much scepticism as I could express. ‘No-one knows anything about Aesop Allen.’

‘Not true. The one thing known for sure is that he came from Shuckleigh.’

‘Well, that much, yes, but—‘

‘This pen has an impeccable provenance. I purchased it from a member of the Hollister family, and it is accompanied by a contemporary note.’

Mosse flipped open a velvet-covered flap in the lid of the box and an old piece of paper slid into his hand. I unfolded it and read what was written on it in black ink in a clear, but undoubtedly Victorian hand.

‘This pen was given to me by Aesop Allen as a token of our deep friendship. With this pen, Aesop Allen wrote Harrow Hall and other famous books. H. Hollister.’

‘Harrow Hall,’ I said, that terrifying work about primeval fear ripping apart the rational veneer of Victorian country life.

My fingers trembled as I refolded the paper and presumed to pick up the pen.

‘It looks quite ladylike,’ I said. ‘Some people say that Aesop Allen was a woman.’

‘Feminist piffle!’ snapped Mosse. ‘The muscularity of the prose completely rules that out.’

I did not judge it wise to pursue the point, and I forgot about it as I felt the pen vibrate with possibility in my hand.

‘H. Hollister was Hester Hollister, wife of the Rev. Mordechai Hollister of St Marys.’

‘Ah yes,’ I said. ‘I have heard of him, and the dates would be right, but can you be sure of the attribution?’

‘It is absolutely authentic. The family have shown me other documents which attest to that. Hester Hollister evidently knew Aesop Allen very well. Indeed, she may have been the only person who knew his true identity.’

Mosse knew me too well, I realised.

‘What are you asking for it?’

He named a sum that caused my vision to blur at the edges. Then he prised the pen from my fingers and returned it to the box with the note. Smiling, he placed it back in the locked cabinet.

‘It is a unique item directly associated with one of the greatest gothic novelists of the nineteenth century,’ he said. ‘I am afraid the price is non-negotiable.’

The pen that had written Harrow Hall. I went home and reached for my first edition of the book, a modest small octavo bound in green cloth, its exterior not hinting at the dreadful events recounted in its pages, unlike the editions of the 1890s with their vulgar illustrated boards. I did not open it. I have never opened it since the day I finished reading it. I do not need to.

The next day I got in touch with every Hollister still living in Shuckleigh, and they all confirmed the provenance of the pen.

I bought it, of course, as Mosse had known I would.

For months I investigated the life of Hester Hollister, but alas, there was little to be discovered. She was the wife of a clergyman who evidently discharged her duties and left no mark on the records of the town, other than her mere existence. The local records office and the museum held a number of local Victorian diaries, but though I spent a full month reading them I found only a few innocuous references to the lady, and no hints at all about her close friendships.

The pen itself I kept locked in my desk drawer and hardly dared to look at it. All the demons of Harrow Hall rose up in my mind when I thought of it. So pretty and slight a thing to be responsible for bringing such nightmares into the world.

If you have read the book itself, you will recognise that in writing this account I have fallen into using the language of the story. Decorous, formal and precise — but I am unable to conjure up such horrors as Allen did, when writing with a biro purchased from W.H. Smith.

I bought a bottle of real ink and a pad of good paper and sat down at my desk to try my hand at writing a ghost story. I had a little idea and thought that, if I got the atmosphere right, I might be able to make something of it.

Taking up Aesop Allen’s pen, I dipped it into the ink and sat a while, pen poised over the top sheet of paper, trying to compose my first sentence.

I came back to consciousness an hour later by the clock above my desk, my right hand stained with ink and four pages of closely-written text before me, the ink still wet in places.

I could not remember writing a single word of it, and worse, the writing was not my own. It was a story called ‘The Relic’, and the central character was myself. I read how I became obsessed with a haunted pen, trying to wring unearned talent from beyond the grave, until the dead turned on me. I was found murdered, and the instrument of my death was the very pen I still held.

Hastily folding the hand-written sheets, I pushed them into the desk drawer along with the pen, and locked it.

No matter how hard I scrub my hand, I cannot get the ink stains out. Every night I dream the events of the story and see myself dead on the floor of my study, a pearl-handled pen stuck in my neck, the pool of blood growing around me blackened with ink.

I would burn the story and the pen, but first I would have to unlock the drawer and let it out, and I am too afraid to do that.