Dear Dr Fang, wrote Marigold Chew, I am writing to you, as the most eminent brain-quack I can think of, to ask for your help. Dobson has gone doolally. Yesterday he was as right as rain – a curious phrase, I grant you, but let us not dwell upon it – sitting at his escritoire scribbling away, then trudging along the towpath of the filthy old canal in the pouring rain, chucking pebbles at swans.

He remained reassuringly Dobson-like at breakfast this morning, tucking into a bowl of boil-in-the-bag koala bear brains ‘n’ mashed plums and blathering inconsequential poltrooneries, just as he always does. It was only when he drained the last dregs from his tumbler of post-breakfast Squelcho! that I noticed something amiss.

Instead of putting on his Uruguayan Notary Public’s boots and crashing out of the door into the teeming downpour, as I expected him to do, he stayed sitting at the breakfast table, a thin smile playing about his lips, a fat beetle scuttling through his bouffant, a blob of marmalade on his cravat.

“Look! Can you see it, O my cherished bundle of utter loveliness?” he said, pointing at a corner of the room.

I could see nothing, save for some dust.

“It is my little man, my homunculus. He has been following me about, in his satin and tat, in his frock coat and bippety-boppety hat. He whispers words I can never quite hear.”

I asked Dobson what on earth he was talking about. He continued to prattle.

“Even were I able to hear him, I am not sure I would be able to understand his whisperings. Not only is he a foreign little man, from remote and distant parts not shown on any map, but he always whispers with his mouth full. He is forever stuffing his gob with smokers’ poptarts, of which he seems to have an endless supply. Have you noticed any packets missing from the larder, O my buttercup?”

“You mean the pantry, Dobson,” I said, “No, I have noticed no such thing.”

“Larder, pantry, pantry, larder,” he went on, excitably, “Sofa, cushions, chaise longue, pouffé. Lay me place and bake me pie, I’m starving for me gravy. Leave my shoes and door unlocked, I might just slip away. If I slip away, perhaps I can escape my little man. But it’s likely he will follow me. God knows, I haven’t been able to shake him off these past seventeen years.”

It was at this point that I asked Dobson if he had taken leave of his senses. But he ignored the question.

“He came seventeen years ago, and to this day he has shown no intention of going away,” he said, “Sometimes he moves his arms as if they were the propellers on a seaplane, the Gnome Omega-powered Fabre Hydravion, for example. I have to place extra paperweights on my escritoire when he does this in close proximity to it, to prevent my papers being blown away. Are you sure you can’t see him?”

I assured Dobson that I could not.

“I think the propelling of his arms is an attempt to dry his hands,” he continued, “His palms are horribly moist. Indeed, for such a tiny man he is surprisingly moist in every particular. Yet whenever he follows me into the bathroom, he shuns the towels. They seem to frighten him, as nothing else does. Imagine that, being frightened of towels! Tea-towels, too, especially those of a souvenir variety, bearing depictions of important buildings and tourist attractions. Once he vomited all over the tea-towel we bought in the gift shop at St Bibblybibdib’s Cathedral. When I tried to launder it he snatched it away from me and tore it into strips and fed it to his chaffinch.”

“What chaffinch?” I could not help but ask.

“There, perched on his shoulder, tiny but weirdly luminous. It is the only chaffinch I know that glows in the dark. Or eats linen. Or monkeys. It ate the little man’s little monkey, which he kept at the end of a length of string, during the Tet Offensive. It ate the string too. It is quite a chaffinch!”

By now I was convinced that Dobson had gone doolally. Thinking a violent bash on the head might bring him to his senses, I went to fetch a hammer. When I returned, there was no sign of him, and the front door was ajar. I looked in the shoe cupboard, but all of his many many many boots were lined up neatly along the bootesquade. Had Dobson done the unthinkable, and left the house in his socks?

Indeed he had. Towards midday, also known as noon, when the hands of the clock both point upwards in an uncompromising vertical, I received a call from the seaside police. Dobson was sat on a pier, bootless, cradling in his arms the limp body of a strangled eel, and staring out to sea. His socks were wet, his cravat was awry, and there were traces of choc ice around his mouth. A ring of lumpenproles had gathered to taunt him. I rushed out and jumped aboard a charabanc heading for the seaside.

The police had removed Dobson from the pier and installed him in a cubby within the seagull sanctuary. I had to use all my powers of persuasion to get past the armed security guards. I found Dobson sprawled on a bunk looking bewildered.

“Wincklemann is gone!” he cried.

“Wincklemann?” I asked.

“My little man, my homunculus,” he said, “He followed me at a trot all the way to the seaside, and while I was at the kiosk on the pier buying several choc ices he lost his footing and fell from the pier into the sea, the sea, the terrible vast wet sea. I fear he drowned therein, my little man.”

It occurred to me that if Wincklemann were as tiny a man as Dobson claimed him to be, it was likely that he was so light in weight that he would bippety-bop, like his hat, upon the water, rather than sink. Then it further occurred to me that Dobson had gone doolally, and that this purported homunculus was nothing but a figment of his fuming brain. I was still carrying the hammer, so I gave Dobson a smart crack on the head with it, hoping to restore his reason.

Alas! The hammer blow had quite the opposite effect. While rubbing his bonce, Dobson gazed into the corner of the seagull sanctuary cubby and let out a joyful yell.

“Wincklemann! You have escaped from the clutches of the wild wet sea! Where once you were moist, you are now soaked to the skin. Were you not fearful of towels I would dab you dry. But I am so happy to see you. What is that you are whispering to me in your foreign guttural tongue?”

Of course, there was nothing in the corner except for some dust and a stray seagull feather. After signing some papers, and feeding cream crackers to an injured seagull, I was allowed to bring Dobson home. It is now early evening, and he has insisted on setting a third place at the dinner table, and carefully portioning out a helping of jellied hare ‘n’ jugged eels ‘n’ jagged shards of frozen celery for his invisible little man. I am at my wits’ end, Dr Fang, or at the end of my tether, whichever end is likely to snap first, and I need your help. Please come at once.

*

Dear Mrs Wincklemann, wrote Dr Fang, At your request, I have conducted an examination of the brain, for which my fee is forty-five panes, ten soilings, and sixpins. Please pay in cash by midnight, or I will confiscate the brain and place it in a jar in my cupboard o’ brains, cackling as I do so.

It is my considered opinion that you are suffering from a common malady, viz. indulging a phantasy that you are a personal friend and confidante of the twentieth century’s titanic, if out of print, pamphleteer. In your case, there is an intriguing level of displacement, where you imagine it is not you, but your husband, who is bosom pals with Dobson. Incidentally, your husband is indeed an extremely tiny little man who could easily be mistaken for a homunculus. Perhaps that is what caused the illusory vapours in your brain.

As I say, it is not unusual for insignificant riffraff such as yourself to attach themselves to illustrious figures such as Dobson. I know of another patient who spent many years convinced she was on intimate terms with octogenarian Francophile pop songstress Petula Clark. If you take the pills I have given you, six per day for seventeen years, your symptoms will surely alleviate. I also recommend close reading of Dobson’s pamphlet At No Time Did I Ever Cradle In My Arms The Limp Body Of A Strangled Eel Upon A Pier While Taunted By Lumpenproles, And I Have Signed A Legal Affidavit To This Effect; And Other Essays, Together With A Spirit Photograph Of Petula Clark Holding Hands With A Homunculus (out of print).