Some brides have a precise vision of what their big day will look like, from the exact shade of cream linen napkins to the number of roses in their bouquet.

But for all the delight I took in planning my wedding day in 2018, I had only two must-haves: that I would marry Chris, then my partner of four years, with my best friend Emma by my side as chief bridesmaid.

Yet when that October day arrived, there was a space at the altar and an empty seat on the top table where she should have been.

Emma's absence still shocks me.

Of course, the run-up to a wedding can be fraught if the bride becomes a diva. Arguments happen. But Emma and I had not had a petty fallout. She had betrayed me deeply, in a treacherous act worse than any a man could have inflicted. She disappeared without trace after Chris, now my husband, and I loaned her £5,000, a third of our hard-saved wedding fund, to help pay off her spiralling debts.

It may not sound like a fortune, but Chris and I have always been careful with our money. We both have good jobs in marketing and tech respectively, but didn't want to blow a fortune on one day. So we set a budget of £15,000 – with a small contribution from my parents for my dress – and stuck to it.

We agreed Emma could pay the money back in interest-free instalments. But in the end she made just four payments, totalling less than £1,250 – before vanishing entirely.

She ghosted my countless attempts to contact her, and disappeared from social media. Indeed, I've not spoken to her since. It was as if she had evaporated.

The £5,000 she borrowed had been sitting safely in our bank account ready to pay the final balances for cars, flowers and the like a couple of months before the big day

Emma ghosted my countless attempts to contact her, and disappeared from social media. Indeed, I've not spoken to her since. It was as if she had evaporated.

I was devastated she could do this to me. The £5,000 she borrowed had been sitting safely in our bank account ready to pay the final balances for cars, flowers and the like a couple of months before the big day.

As the wedding approached, rather than buzzing with anticipation, we had to make difficult financial decisions to try to fulfil contracts already signed.

Worse, though, than all this is that a friendship I treasured was cast aside.

After all, since the day we met in university halls of residence in Sheffield, Emma and I had been nothing less than soul sisters.

Our bond had been instant, cemented by us never once having a cross word in the 13 years we'd been friends. Now in our early 30s, we never stopped laughing. I was girly, she was more of a tomboy – together we were the perfect balance.

I felt I knew her inside out – I trusted her implicitly. Yet she let me down and abandoned me, and over money, too. She disappeared owing us £3,750, a measly sum in the wider scheme of things, but that wasn't the point.

It's almost worse that Emma didn't ask for a loan, or even vaguely hint at needing a bail-out. Both Chris – who I met in my third year at university – and I had known her since our Sheffield days, and we had both become aware of how perilous her finances were after graduating.

Emma just loved to spend and made poor financial choices. She bought smart sofas and the latest televisions on credit cards or through payday loans. It all meant she ended up paying way over the odds for each item.

Emma just loved to spend and made poor financial choices - both my husband and I were aware of how perilous her finances were after graduating

She was such a hard worker – putting in long hours as a PA to an architect – yet her wage barely covered the rent and bills.

A lazy, live-in boyfriend, who wasted a fortune on bets at the bookies and drinking, only made matters worse. He contributed nothing to her life, emotionally or financially. She would talk to him, he would promise the world – but if he did get a job, it wouldn't last. He'd be late for shifts or blow his wages.

By the time Chris and I were planning our wedding, she was paying a small fortune each month in interest alone on high interest credit cards, payday loans and even to a loan shark. It was very worrying.

Chris, now a project manager, and I had dated for a while at university, but I graduated a year before him and moved to Birmingham in 2011 to take up my first job in an advertising agency.

We stayed in touch as friends, before getting back together in 2014.

In the meantime, Emma had moved to Leeds, but we remained close despite the distance.

Over Christmas 2016, Chris proposed. Emma was thrilled for us, doubly so when I asked if she'd be a bridesmaid alongside Gina, my oldest friend from primary school.

'I'd have been offended if you hadn't asked me!' she laughed. I couldn't imagine getting married without her – not just on the day, but in relying on her advice in planning our church wedding and celebration in a country hotel.

Aware that her financial struggles were deepening, with interest on loans which I guess amounted to around £10,000, I reassured her we'd pay for her bridesmaid dress, shoes, hair, make-up and a hotel room for the night. She was visibly grateful, admitting that 'money is a bit tight at the moment'.

It was shortly after this that we decided we had to help her.

With the wedding deposits paid in spring 2017, we had another £5,000 sitting in our savings we wouldn't need to touch until just before the ceremony in October 2018.

If we offered that to Emma, we reasoned, by the time our wedding came around she'd be on her way to being debt-free, able to enjoy her bridesmaid role knowing she would soon be able to start afresh. She might even have the courage to ditch the boyfriend.

We put our proposal to her after lunch at a village pub near her home in Leeds.

Clearly overwhelmed, she hugged us both and wept, telling us: 'You have no idea what this means to me.' It was, she said, 'life-changing'.

'I will repay every penny in full and on time,' she added, when we showed her the repayment plan we'd drawn up: £312 per month for the next 16 months in the run-up to our wedding, interest-free.

At that moment, I felt closer to her than ever, sure we'd done the right thing. Even though she explained that it wouldn't wipe out all her debt, she said it would enable her to start paying off the loans themselves, rather than only ever being able to meet the interest.

Later that day, she sent heartfelt text messages saying how much our kindness meant, promising again: 'I will pay back every penny in full.'

I breathed a sigh of relief. For while our offer had been made gladly, in all honesty I also wanted our wedding to be a calm occasion. I didn't want to ask Emma to help me plan dinner menus if she was horribly stressed.

Ironically, I also worried for our friendship – I didn't want her to resent us spending thousands of pounds while she was struggling. More than anything, I wanted her to have a clean slate.

I can't help but feel like a fool today.

For the first four months, Emma paid us back on the dot with the agreed £312.

But when months five and six came and went without a payment and Emma stopped answering my calls or responding to messages, I became concerned. Had something happened to her?

Every message I sent was met with silence – from basic 'Hope you're OK' texts, to emails trying to make a time for her bridesmaid dress fitting.

Eventually, frantic with worry, I messaged Emma's mum on Facebook asking if she was OK. She didn't reply, even though I could see she'd read the message.

I messaged her boyfriend. He told me they'd been evicted, split up and he didn't know where she was, then didn't reply to any subsequent messages. I even tried messaging some of her other Facebook friends, but they either didn't reply, or said they didn't know where she was.

I suspected she had probably gone home to her mother's house in Cumbria. We thought about just turning up on the doorstep there but I was just too upset about it all.

The weeks ticked on with zero contact from Emma and no payments into our account.

Eight months before the wedding, I sent one last message: 'The door is open, I still want you involved, we can put the money to one side if you're struggling, but I just want you to be part of our special day.' Even to this, there was no reply.

Naively, I still believed there was no way she would miss my wedding. But as the day got closer, so did the bills. Eventually, Chris and I confided in my parents about our loan to Emma, and how it had left us short, hoping they would advise us.

Mum and Dad said they would clear the wedding payments for us, but we didn't want that. They'd already paid for the venue and my dress. So instead, we took out a high-interest credit card, which was difficult for us as we'd always tried to be responsible with our money.

As much as I was concerned for Emma, my worry was now becoming anger.

It was like dealing with the worst kind of break-up. I was overwhelmed with emotion. One moment I was seized with concern for Emma, the next filled with fury that she had betrayed our trust.

I remember feeling so enraged one day I said to Chris: 'She can't be dead because it would be in the news, so where the hell is she?'

Today, it seems Emma is alive – she has a very limited social media profile on one platform, and I can see she has children and looks well, but she only posts once a year, if that. None of our mutual friends from university have seen her in years.

I've had to deal with what was effectively a bereavement, grieving for a lost friendship.

She'd been to so many of our family events over the years that, on our wedding day itself, lots of guests asked where she was, surprised by her absence. Chris and I brushed off questions with forced smiles and said she was away travelling.

Our day was beautiful – but the memory is tainted by Emma's perfidy.

After the wedding, we decided to pursue her in the small claims court, which cost around £200.

Perhaps we should have let it lie, but we became more angry that she'd left us high and dry.

Emma didn't appeal when she was contacted by the courts via her mum's address and was then issued with an attachment of earnings order, a court-directed arrangement that required her employer to deduct automatically a given amount of money from her monthly salary to repay her debt to us.

Initially, we were offered just £10 a month, which would have meant our children, now six and four, would be teenagers by the time the debt was repaid. Through the courts, we eventually agreed to around £120 a month and it was finally settled in full last year.

But the debt being cleared doesn't soothe the pain – the money has always been secondary to the sadness I felt for losing my beloved friend.

Today I still torment myself, wondering whether I could have handled things better. Maybe I should just have written off the money. I even wonder whether I wasn't a good friend after all and that's why Emma cut contact.

In my more rational moments, deep down, I know that getting so hopelessly into debt – not to mention the useless boyfriend – points to a darker side to her personality (I've heard on the grapevine that drugs and gambling could have been involved).

But I still worry for her and feel guilty about the distress she must have felt at receiving the court letters. It was our money though and, more painfully, she'd destroyed our friendship.

On her birthday and at Christmas, I wonder if I should try to make contact. Despite the deceit, I feel sorry she's no longer part of my life. My two gorgeous children will never meet her.

Then I remind myself it's been years now, and we could never truly repair the damage. Emma's was the most seismic act of treachery – from the one person I believed would never let me down.

Abigail Smith is a pseudonym. Names and identifying details have been changed

Interview by Sadie Nicholas