“Good heavens,” she says, “just how much detail do you need?”

But although it worked for European royalty, it isn’t going to work for Pappa-it is only if one party complains about the other party’s inability or refusal to consummate the marriage that non-consummation becomes a ground for annulment or divorce, the trainee solicitor writes in a clumsily worded letter.

“Well, I never knew that,” says Vera, who thought she knew everything about divorce.

Valentina laughs out loud when Pappa suggests a divorce. “First I get passport visa, then you get divorce.”

Pappa, too, has gone off the idea of divorce. He is afraid that they will question him about squishy squashy. He is afraid the whole world will find out about flippy floppy.

“Better think of something else, Nadia,” he says.

Despite the stress he is under, he has managed to finish another chapter of his history, but it has taken on a sombre tone. When Mike and I visit at the beginning of February, he takes us into the sitting-room, still full of last year’s apples and as chilly as a cold store, and reads aloud to us.

The early makers of the tractor dreamed that swords would be turned into ploughshares, but now the spirit of the century grows dark, and we find that, instead, ploughshares are to be turned into swords.

The Kharkiv Locomotive Factory, which once produced 1,000 tractors a week to feed the demands of the New Economic Plan, was relocated to Chelyabinsk beyond the Urals and converted to produce tanks by decree of K. J. Voroshilov, the People’s Commissar for Defence.

The chief designer was Mikhail Koshkin, who was educated at the Leningrad Institute and worked at the Kirov Plant until 1937. He was a moderate, cultured type, whose genius was used, one might say abused, by Stalin to create the Soviet Union ’s military supremacy. Koshkin’s first tank, the Aso, ran on the original caterpillar tracks, with a 45-mm gun and armour that would withstand a hit by a shell. This was renamed the T32 when the gun size was increased to 76.2 mm and the armour was also made thicker. The T32 saw action in the Spanish Civil War, where the thinness of the armour plating made it vulnerable, though its manoeuvrability was much admired. Out of this was bom the legendary T34, which many credit with having turned the tide of the war. It had even thicker armour, and to compensate for the additional weight, was the first locomotive to be fitted with a cast aluminium engine.

His voice is weaker, more quavery, and he has to keep stopping for breath.

In the ferocious weather of February 1940, the first T34 was driven to Moscow to be paraded before the Soviet leadership. It made a huge impression, not least because of the way it rolled so smoothly over the rutted, cobbled, snow-bound streets of the capital.

However, poor Koshkin did not live to see his creation in production. On this trip, being exposed for many hours to the abominable weather, he contracted pneumonia, and died some months later.

The design was completed by his pupil and colleague Aleksandr ‘ Morozov, a dashing and handsome young engineer. Under his guidance, the first T34 tanks rolled off the assembly line in August 1940, as they were soon to roll off in their hundreds and thousands. In honour of this, the town of Chelyabinsk, formerly most noted for production of tractors, was renamed Tankograd.

Outside the window, the sun sinks into the frosted furrows which have not thawed all day. The wind that nips the branches has blown in from the flatlands of the East Anglia coast, and beyond that from the steppes, and beyond the steppes from the Urals.

My father is warmly wrapped against the cold with fingerless gloves and a woollen hat and three pairs of socks. He leans forward in his chair, reading through his thick glasses. Behind him on the mantelpiece sits a portrait of my mother. She is looking over his shoulder, out towards the fields and the horizon. Why did she marry him, this musing brown-eyed young woman with coiled, plaited hair and a mysterious smile? Was he a dashing and handsome young engineer? Did he seduce her with talk of automatic transmission and gifts of engine oil?

“Why did she marry him?” I ask Vera.

Mrs Divorce Expert and Mrs Flog-‘em-and-send-‘em-home have been swapping notes on the phone, and the tone between us has become quite cordial. We moved from talking about our father’s marriage to Valentina to our parents’ marriage, and now I see the door to the past has opened a crack, and I want to push.

“It was after the submarine commander was killed at Sebas-topol. I suppose she was frightened of being on her own. It was a frightening time.”

“What submarine commander?”

“From the Black Sea Fleet. Whom she was engaged to.”

“Mother was engaged to a submarine commander?”

“Didn’t you know? He was the love of her life.”

“Not Pappa?”

“What do you think?”

“I don’t know,” Bogey-nose whines, “no one ever told me anything about it.”

“Sometimes it’s better not to know.”

With a snap, Big Sis closes the door to the past and turns the key.

A date has been set for Valentina to appeal against the Immigration Service decision. Suddenly my father realises he is not so powerless after all. The appeal is to be held in Nottingham in April.

“I’m not going,” says Pappa.

“Yes you go,” says Valentina.

“You go by yourself. Why I shall travel to Nottingham?”

“You foolish man. If you no go, immigration bureaucraczia will say, where you husband? Why you no husband?”

“Tell bureaucraczia I am sick. Tell them I will not go.”

Valentina gets advice from her solicitor in Peterborough. He tells her that her case will be seriously compromised if her husband does not go, unless she can produce evidence of his illness.

“You sick in head,” says Valentina to my father. “You causing too much trouble. Too much crazy talking. Too much kiss kiss. No good eighty-four-year man. Doctor must write letter.”

“I am not sick,” says Father. “I am poet and engineer. By the way, Valentina, you should remember that Nietzsche himself was considered to be mad by those who were his intellectual inferiors. We will go to Doctor Figges. She will tell you I am not sick in head.”

The village doctor, a softly spoken woman approaching retirement, has treated my mother and father for twenty years.

“Good. We go to Doctor Figges. Then I tell Doctor Figges about oralsex,” says Valentina. (What? Oral sex? My father?)

“No no! Valya, why you must talk about this to everybody?” (He doesn’t seem to mind talking to me!) “I will tell her eighty-four-year husband want make oralsex. Squishy squashy husband want make oralsex.” (Please Pappa-this is making me feel a bit queasy.)

“Please, Valenka.”

Valentina relents. They will go to a different doctor instead. Valentina and Mrs Zadchuk bundle my father into Crap car. They are in such a hurry to get to the surgery before he changes his mind that his coat is buttoned up out of kilter and his shoes are on the wrong feet. Instead of his distance glasses he is still wearing his reading glasses, so everything passes in front of his eyes in a blur-the rain, the flicking of the windscreen wipers, the misted-up car windows, the smear of hedgerows as they pass. Valentina sits in the front, driving in her wild self-taught way, while Mrs Zadchuk sits in the back hanging tightly on to Nikolai, in case he decides to open the door and fling himself out. So they career around the narrow country lanes, splashing through puddles, sending a couple of pheasants running for their lives.

They do not take him to Doctor Figges at the village practice, but to a neighbouring village where there is another branch of the same practice, but staffed by a different GP. They are expecting to see the middle-aged Indian doctor, but instead there is a locum. Doctor Pollock is young, red-haired and very pretty. My father does not want to discuss his problems with her. He peers at her myopically through his misted-up reading glasses, and tries to change his shoes around without her noticing. Valentina does all the talking. She is sure the young woman will be sympathetic to her case, and she goes into some detail about my father’s strange behaviour-the coughing, the Toshiba apples, the tractor monologues, the persistent sexual demands. Doctor Pollock looks intently at my father, notices the odd shoes, the staring eyes, the mis-buttoned coat, and asks him a number of questions: