Two years ago today Leah Croucher vanished off the face of the earth in Milton Keynes. This is why it's the most emotive story I've ever written

She'd gone to work and failed to come home, they said. Wondering why police had put this out on a Sunday, a rest day, I half-heartedly pondered whether or not it was worth getting out my laptop and popping a story online.

With the battle-scarred wisdom that comes from parenting three teenagers, my first thought was: 'She's 19... The little monkey is probably having a whale of a time partying somewhere and will turn up on Monday morning, bleary-eyed and repentant with the dubious excuse that her phone ran out of charge'.

How very wrong I was. And how right police were to take this case seriously, right from the start.

The young woman's name is Leah Croucher. Two years on, her case has become one of the most agonising, frustrating and baffling stories I have ever had to write in my 44 years as a local paper journalist. Like thousands of other people, I can honestly say there is scarcely a day goes by when I don't think of Leah and wonder what has happened to her. Is she still alive? Did somebody abduct her? Why have none of her possessions been found? How can somebody vanish so suddenly and so completely from a bustling built-up area of Milton Keynes at peak commuter time on an ordinary workday morning?

Today, after 730 days of intensive police investigations, fingertip searches, lake dives and desperate appeals, all those questions remain unanswered. The stark reality is that there has not been a single clue or a single shred of evidence to shed any light on the biggest mystery this city has ever seen. Police know nothing now that they didn't know two years ago: Leah is gone. That's it.

Journalists aren't mean to feel things too much; we shouldn't get overly emotionally involved, we're told. But after two years of talking to Leah's family, the gentle, loving and respectful people that clearly worship her, I defy anybody not to feel their pain. Month after month, I ask her parents if there is any news, anything they want to say. Month after month they rack their brains for something that hasn't been said before, something they may have missed as they re-live the last days and hours they spent with Leah, over and over again, like a form of torture when they've already been tortured more than any family could bear.

We seize upon minor details. The way Leah ate a takeaway Chinese meal for her dinner the night before, Valentine's night, because her mum was cooking her dad's favourite meal, which she didn't like. The way she joked with them about their Valentine's gift; the things she said, the film she watched, the jokey social media exchanges with big sister Jade. We all talk about Leah in the present tense, but sometimes, tragically, a past tense slips in.

On good days there's hope. Maybe the wholesome, home-loving, slightly shy Leah that had to be cajoled to visit a pub when she reached 18 ("Pubs aren't really for me" was her verdict) dramatically switched personna, disappeared voluntarily and and is hiding somewhere, ignoring all the media appeals and shunning the family she loved. As hard as that may be for parents John and Clare to contemplate, that is the best scenario they have.

The second scenario is that Leah was abducted and is being held against her will. It's an horrific thought, but there's at least a glimmer of hope that one day she will break free and manage to contact her family. "She knows her dad's mobile phone number off by heart. She wouldn't forget that, would she? She'd call," says Clare, who has to balance that optimism with the reality of what horrors her daughter could be facing every day if this were the case.

A mystery man, who can only legally be referred to as 'Mr X', plays a strong part in this second hypothesis as far as Leah's parents are concerned. They say there is evidence Leah was romantically involved with this man, who was older and engaged to be married at the time. Uncharacteristically, Leah had lied about meeting him, they say.

But the man has since denied they were in a relationship. And police say there is no evidence at all to suggest that anyone played a part in Leah's disappearance.

On terrible days there's the third scenario - darkness. If Leah is no longer with us (nobody can bear to say dead) then we want her home, where she belongs, so we can say a proper goodbye, say her parents. But this is too heartbreaking to contemplate, particularly for a family that has already experienced the indescribable pain of losing a child.

In November 2019, nine months after Leah was last seen, her half brother Haydon - John's only son - took his own life. He had become increasingly tortured and frustrated about the lack of progress in finding Leah, and the family had sought help from mental health services. He'd been discharged from MK's acute mental health team days before his death.

"We started this year with three beautiful children and a world of hope at our feet", said John at the end of 2019. The stark phrase running through his head, driving him insane, was: "Two, we've lost two".

Amid the heartbreak there was hope that Leah, if she were in hiding, would be jolted into reality and attend the funeral of the brother she adored. It was not to be. Other milestones came and went - two Christmases, her 21st birthday last August, when Clare sobbed because she should have been buying her daughter a beautiful piece of jewellery to celebrate - but there was still not a whisper of Leah.

Meanwhile, the 'Have you seen Leah' banners put up by the family in the early days still flap desolatingly from bridges around MK. Occasionally I spot a tattered 'Missing' poster, cut from the Citizen's front page, still loyally Sellotaped to the window of a car. It was our aim to get people to copy it so it was displayed on cars and windows all over the UK. It didn't bring Leah back.

In Milton Keynes, the name Leah Croucher is pretty much universally known. She's 'our' Leah; we care deeply about finding her, feel incredible sympathy for her family, and hold endless hypothetical discussions about what could have happened to her. Most of all we long for this girl, a girl that most of us did not even know, to be found safe and well.

What has always puzzled me, however, is that so many people outside of MK don't seem to know about our Leah in this cyber connected world. Why hasn't our missing person mystery received the same massive publicity as Suzy Lamplugh, for example? Is there someone out there, miles and miles away, that could hold vital information but is totally unaware of how important it is? All we can do is spread the word, share, share and share again the social media appeals and photos of Leah's smiling rosy-cheeked face.

There's a £10,000 reward for any information that leads to Leah being found. One Tweet, one Instagram post, one Facebook share could make all the difference.

"I actually thought I'd found her via Instagram a while ago," reveals the police officer in charge of the Leah investigation, DCI Andy Howard.

"Someone saw an post of two girls in South East London. One of the girls was called Leah Croucher and bore a striking resemblance. It was a different haircut and there were physical differences, but she really looked like Leah.

"We showed Leah's parents. They didn't say 'yes, it could perhaps maybe be her.' They said 'Yes. That's Leah'."

Excitedly police did some more investigations through detective work and Instagram. The photo was genuine. The girl was genuine - but it wasn't Leah.

"Yes, there is actually another girl called Leah Croucher, living in South East London, who bears a really strong resemblance to Leah," sighed the DCI.

He has vowed never to give up on finding Leah. "The case sometimes keeps me awake at night," he confides. I know the feeling. This is one journalist who is, unashamedly, far too emotionally involved in this case.

We WILL find Leah, and I will keep repeating the sentence I must have written 100 times: 'If you know anything at all, no matter how small, please call the police on 101 or Crimestoppers anonymously on 0800 555 111.'

To anybody who feels they can substantiate the scenario two theory, and thinks they have evidence that someone was involved in Leah's disappearance, I will repeat the plea from Leah's family: 'Please, do the decent thing and put us out of our misery.'

To Leah herself, if she is out there, there are just four words from myself and all the people of Milton Keynes: Sweetheart, please call home.