Five-minute memoir: Hannah Richell recalls a climb in Anglesey that went horribly wrong

He was the family hero. Then the unthinkable happened...

A winter's morning in Sydney. I wake to the phone ringing downstairs – too early for sunshine or birdsong. Too early for good news. My daughter's wailing half-drowns the careful message being left on the answer machine. My mum: some news – please call. In the living room, my son attempts to scale a bookcase. "Get down," I say, pouring cereal into bowls and juice into cups, knowing I'm delaying the announcement of something unbearably sad. Finally, with kids settled, I head for the phone. "Tell me," I say.

"Jack," Mum says, her voice cracking. "It's Jack."

I was 15 when my cousin Jack was born and I remember him well: an outdoor kid, all rosy cheeks and muddy wellies, tottering round stable yards, chasing after the family spaniel. We shared Easter eggs and Christmas crackers, played charades and blew out birthday candles. We flew kites at West Wittering and walked high up on to the Sussex Downs.

At my sister's wedding, young Jack skidded across the dancefloor in smart little boy clothes, hyper on late-night lemonade. He was a sweet-looking kid and precociously bright, his young head full of facts and figures, capable of beating even my brother-in-law at chess (and once biting him when he didn't). He was the baby of the family and the apple of my granny's eye, one of those kids you just knew was going places.

I went places too – to university, to London, then on to Australia to start a family of my own. Jack drifted in and out of my life, or perhaps I drifted in and out of his. Time and distance unpicked some of the threads that had bound our family so tight, until, one day, a shock: "My God… you're so tall!" Jack grinned down at me – his mother's smile, eyes full of his father's easy charm. "And your hair! Bloody hell."

Over lunch, as Jack steadily ate his way through the contents of Gran's fridge, I learnt more about this giant cousin of mine. No longer a boy, he was now a bold adventurer, full of ideals and morals. No meat, thank you. No car, on principle. Instead, he'd hitchhiked over a hundred miles to be with us that day. His passion for the environment was obvious, his knowledge of science and the natural world dazzling. He could make a surf-kite or a bike from scratch. It struck me then how unusual he was, a young man in his early twenties who knew so clearly who he was and what he stood for.

He was energetic too, a man of motion: cycling, running, surfing and, his greatest passion, climbing. We saw the scrapes and bruises, the surgery scars he'd earnt from a bad fall in 2009 which had delayed his ambition to free-climb El Capitan in Yosemite, to raise funds for a Multiple Sclerosis charity; but he was climbing again, a feat the doctors told him he would never achieve. I envied him his passion, his ability to be so present, to live each moment fully.

The kettle went on, and Jack, never one to sit for long, offered to take the dogs and my son for a run in the park. When they returned, the boys wore matching grins. They'd found a climbing frame and Jack had taught Jude a technique or two. "He's good," Jack proclaimed, "a natural." My three-year-old gazed back at him: a living, breathing superhero.

Jack's last climb was in June this year. He'd just finished his first-year biomedical science exams at university – on track for a first-class degree, they say – and was in Anglesey for the weekend with friend and former teacher, Vaughan. Both men were talented climbers. They set out in fine weather, their rucksacks filled with the necessary equipment, abseiling down a cliff face at North Stack before beginning their ascent back up. It should have been a textbook climb.

The alarm was raised at 10pm, when Jack and Vaughan failed to return. A search was mounted and two rucksacks retrieved, but hindered by bad weather, the effort was postponed until first light. The following morning, at 7.15am, a RNLI lifeboat recovered two bodies from the sea: Jack and Vaughan, still roped together. It was Sunday 16 June – Father's Day – not quite two weeks since Jack's 23rd birthday.

It's impossible to know what happened on that cliff face, but we've all been falling ever since – into the gaping hole Jack's death has left behind. But not Jack; he won't fall again; he won't break another bone, won't even skin his knee. Instead, his unique spirit soars in our memories, like the kite surfers still skimming the waves, like the sparrow hawks he loved so well.

Hannah Richell's latest novel, 'The Shadow Year' (Orion, £7.99), is out now