They found the diaries in open view on the rickety brown book-shelf in the little upstairs flat in Shepherd’s Bush. Plain navy covers, nothing special to look at, but my mother and my aunts were fascinated, and the Oldest Sister, pulling stripes of family rank, put them in her handbag, glancing over her shoulder to see if Grandad had noticed. In fact, he was in the kitchen, looking for biscuits in the big, round tin which was where it always was, on the table next to the tea-pot.

I could see everything from my perch on the shiny hard sofa with its anti-Macassars: the sisters moving from shelf to shelf, picking up pieces of china and putting them down again, waiting for the boxes to arrive which would consign ninety years of life to neat parcels in the past.

Without understanding the mechanics of it, I could have told Grandad – who was, incredibly enough, Great Grandad’s little boy – that there would be no more biscuits in that round tin and the old stained tea-pot would never steam again.

I was four years old then, and I knew Great Grandad was gone, but didn’t know where or how. This was his space and although still full of the things he had gathered around him, the heart of it had gone.

It was like when I found my rabbit, Sooty, lying flat and still in his hutch, no more flat and still than when he was sleeping – but I knew without trying to wake him, he was gone.

The flat was dead now. The traffic still buzzed in the road below, but the rooms no longer hummed with the noise of living, which had been there even when Great Grandad wasn’t speaking which was, to be honest, a rare occurrence.

What I saw when I thought of when the flat was living, was sunlight spilling on the little kitchen floor and around the table, and on hard chairs which made my bottom numb, sat me, my brother, and Great Grandad, his shock of white hair lit like a halo above arched eyebrows and the blue eyes he had bequeathed to my mother.

He poured us brick-red tea which was too bitter to drink despite six spoons of sugar, and my brother and I ate all the biscuits while Great Grandad pulled up the old sash window and shouted at somebody in the street.

I heard a woman’s thin voice from far below, say: “Open the door – we have a nice hot dinner for you!” but Great Grandad shouted back to her, and slammed the window shut, and I didn’t know why my brother was laughing, rolling on the floor laughing, because I was too young to know what “Fuck off with your hot dinners!” meant.

As the flat was dead now, it seemed there was little that anyone wanted to keep – perhaps because so little in it had mattered to Great Grandad. His little boy – my Grandad – said that all he wanted were the two suitcases from under his father’s bed, which was still rumpled from when the ambulance men took Great Grandad away on his last journey.

In the end, the Uncles brought three big boxes up the steep stairs from the little hallway, but only one was needed, and at the top of the stairs, they turned out the light there, and Great Grandad became part of the past.

From then on, there was a vase on the mantelpiece at home which was our memento of him, Victorian, like Great Grandad himself, in burnished browns and golds, a painting of an improbable sunset over mountains, and the word ‘Sontag’.

But what mattered to the sisters were the diaries, and what they imagined would be written there.

There were seven of them – each with the year neatly painted in some white stuff on the cover – 1939, 1940, 1941, 1942, 1943, 1944, 1945.

What revelations the sisters had expected, from these seven of his ninety years! Great Grandad had had an opinion on everything, and never ceased to share it, so maybe they expected some thoughts about the war; or maybe, as my mother, the most imaginative of the trio, thought, the Big Secret of his break with his wealthy family to marry the sweet, piano-teacher daughter of Gentleman Jim, disreputable artist and drunk, would have been written there.

Great Grandad had written an entry every single day, beginning on 3rd September 1939. But their hopes of epic revelations were dashed: every day, in neat copperplate, he had written the letters JJJ – the initials of his three Christian names, Josephus James John – followed by a brief note of the weather, and the phase of the moon. So these, the sisters said, sighing, were the reflections of their grandfather on vast world events. The diaries ceased to be mentioned – and I don’t know where they are now.

Fast forward twenty-five years, to when my own grandfather went to meet his fathers both earthly and heavenly.

Again, the sisters went to empty an old man’s flat, and again, very little was retrieved. The gold watch and chain he’d worn went to my oldest cousin, and there were some books, and small ornaments which had been buried in dust since my grandmother died. But my brother and I, being curious, each chose to keep one of the two suitcases which had been retrieved all those years ago from under Great Grandad’s bed.

They were battered, cheap, brown cardboard, and locked, but they rattled when shaken, and one afternoon, as my new baby for who this would all be history, slept in her pram, my brother managed to break the locks.

I had chosen the one which had a single white paw-print on it, from when some long-dead cat had obviously bothered a house-painter. It wasn’t full, but what was there was intriguing: some small metal objects, some wire, some old black and white photographs of people I didn’t know, in places I didn’t recognise, an envelope addressed to a London street long bombed to smithereens, and some post-cards with cryptic messages, sent from European countries.

One, a picture of the famous Mannekin Pis statue in Brussels, dated 25th August 1939, and addressed to that long-dead London street, was franked in Brussels, and the message, in the same beautiful copperplate of the diaries, read: Remember to feed the geese before midnight.

Most surprising, a picture of the Brandenberg Gate in Berlin, franked with the Swastikas of Nazi Germany – sent again to that London street – bore the message: The night-shift starts early on Wednesday.

It was dated 31st August 1939 – the day before German troops invaded Poland.

Born and bred Londoner Josephus James John never fed a goose in his life, and what night-shift he was referring to remains a mystery. And we never did trace the address in London.

But why was this sixty-year-old night-school teacher on ‘holiday’ in Europe on the brink of disaster, and above all, what was JJJ doing in Berlin, the day before the catastrophe of WW2 was triggered?

It must be said that JJJ was a man of varied interests. Losing his teaching post along with his family when he chose to stay with his wife and child rather than return to the comfortable fold, he found work as a train-driver. But he continued teaching, after a fashion, at evening classes: he taught Esperanto, deciphering, and short-hand. He compiled cross-word puzzles for newspapers, and learned to speak idiomatic French from refugees.

If the contents of my suitcase were intriguing, what we found in my brothers’ was astonishing.

French occupation coins from 1942, papers – which would have fooled anyone, and apparently did – ‘proving’ that JJJ was a native of three different towns in Normandy and – most exciting of all, a recipe, which at first we thought might be for the most disgusting cake ever made, but which contained items which in combination were explosive, made out of the kind of ingredients which I assume could be found in many households of the time.

The diaries, with the painstaking record of the skies and the phases of the moon, fell into place: JJJ was using the skills of his life, to fight for his country, in occupied Europe.

I didn’t know much about groups like SOE, and I had no computer at the time, but I took my two small children, and my new baby, to the library, and did my research into organisations formed of ‘ordinary’ people who were each in their way extraordinary, having unique skill sets which put them outside the box in everyday life, but made them valuable members of war-time operations.

What I also learned was that membership of these groups was covered by the Official Secrets Act, and therefore, anyone who disclosed their membership to anyone – even their spouse – faced the death penalty.

So JJJ’s suitcases, locked and gathering dust, his mysterious disappearances during those years, his heroism – he clearly worked in occupied France, where the average life-span of an operative was three months – all remained unexplained and unsung.

But not inexplicable. He had children, and grandchildren, and before he died, he had great-grandchildren, too. And those who defend their country against foreign incursion, by whatever means available to them, do it from love of their children, so as to bequeath to them the freedoms they win, along with the colour of their eyes.

When I was four years old, I thought that he was gone. But half a century later, I can remember his voice, telling me not to be afraid, and I can see the splash of sunshine on the flat walls. And tucked away safely, where one day my own grandchildren and great grandchildren will find it, is a suitcase hinting at dramas which are the stuff of legend now.

I believe that people who love and are loved gain immortality.

I don’t know what JJJ had to do, in the cause of freedom. Maybe it wasn’t pretty. Those hands which poured my bitter tea into the cup-and-saucer which were too big for me to handle, would probably have been trained to kill, and each time he “disappeared” he would have known that maybe, this time, it was the last goodbye…and had to pretend it wasn’t, certain that nobody would ever know that he was more than just an everyday hero.

And what he did, he did for love.