On Hallowe'en night, Meredith Kercher (21) put on a vampire's cloak and bright red lipstick and partied with other international students enjoying time in Italy.
She cheerfully posed for a photograph with a friend wearing a mask like the one used by the killer in the horror film Scream, which features US college kids being stabbed to death.
Around 24 hours later the young Londoner was knifed in her own bed. Her throat was cut and police say there was evidence of violent sexual activity.
Since August, Meredith Kercher had been living in Perugia, a romantic hilltop town rising out of the Umbrian countryside. She aimed to master the Italian language and enjoy the freedom of spending a year abroad.
She shared accommodation with an American girl, Amanda Knox (20), who was taken into custody shortly after the murder.
There are other suspects in the case and a widespread belief that whoever killed Meredith Kercher did not act alone. But Amanda Knox, la bella studentessa Americana, remains the most enigmatic figure in the ongoing investigation.
The Italian press has been captivated by this sweet-looking, expensively-educated young woman who has been described as a luciferina with the face of an angel.
And photographs of Amanda Knox are frequently accompanied by images of Pinocchio -- with a very long nose.
The speculation is that, despite her wholesome appearance, Amanda Knox could be la grande orchestratrice of a terrible crime.
Public sympathy greeted the arrival in Italy of Meredith Kercher's broken parents, who called their daughter "Mez". Her father John, a freelance journalist, was clearly touched by the support he received from the press pack covering the crime. But another distraught couple were also making their way to Perugia. When Amanda Knox's bewildered parents arrived from far-away Seattle, the wide-eyed, middle-class pair were visibly struggling to make sense of a nightmarish situation.
Leaks from the investigation meant Italian news outlets could reveal increasingly-salacious details on a daily basis, ensuring that their model daughter had become notorious at home and abroad.
As the claims about what Meredith Kercher may have been subjected to in her final hours grew more and more outrageous, it became harder to separate conjecture from fact. But the tragic incident Amanda Knox was linked to was beginning to have all the appearances of a gruesome group-sex crime. According to the investigating team, Amanda Knox is placed at the crime scene by a bloodstain on a tap.
The investigators also claim that her DNA was found on a knife at the house of her Italian boyfriend, Raffaele Sollecito (23). He was also taken into custody. In photographs, he always appears serious, bespectacled and bundled up in a colourful scarf.
Amanda Knox's short time in Italy may have taught her something of the concept of omertà, the old Mafia code of silence. It was a long time before she said anything at all to investigators.
When she did begin to talk, she pointed the finger at Patrick Diya Lumumba (38).
A well-known figure in Perugian student circles, he is a musician and bar-owner. His short, dreadlocked hairstyle make him look younger than his years. Originally from the Congo, he has been living in Italy for two decades.
Lack of evidence and a solid alibi secured Patrick Diya Lumumba's release and he returned home to his worried family.
At this point the investigators turned up another suspect.
Rudy Hermann Guede (20), a keen basketball player originally from the Ivory Coast but living in Italy, is the most recent entrant into the parade of suspects. He was arrested in Germany and his extradition to Italy was granted this week. He may now have most to fear from the outcome of this case. It has been reported that strong DNA evidence links him to the crime scene.
All the suspects deny charges of murder and sexual assault.
Since the alleged protagonists are barely out of their teens, this has been the most modern of murder investigations.
Text messages sent between the suspects' mobile phones have been analysed for clues. Casually-posted blog entries were treated with equal seriousness. Sites like Bebo, MySpace and Facebook have been scoured for snippets of information that could prove crucial. Such sites have also provided a seemingly-endless stream of photographs of Amanda Knox, which have been reproduced in Italian newspapers.
In one image, cute Amanda poses with a teddy bear. In another, childish Amanda wears a purple beanie hat. And in yet another, coquettish Amanda pulls a pouting face.
Investigators have produced a psychological profile of Amanda Knox which, translated by the Italian news agency ANSA, describes her as having a "multi-level personality" and being "'self-possessed, shrewd, cunning and, at the same time, naive".
She was also said to have no inhibitions and was subject to any impulse, "even those which could lead to uncontrolled and violent behaviour".
Investigators said her boyfriend Raffaele Sollecito was "attracted to violence" and possessed a "complex and, in certain respects, disturbing personality". Meanwhile, Meredith Kercher's name is now as tragically well-known as that of Madeleine McCann. And it has become synonymous with the medieval university town of Perugia.
Buying my train ticket to Perugia, I mispronounced the name of the town. To confirm my destination, the helpful ticket vendor asked a chilling one-word question: "Meredith?"
But life goes on for the international students in Perugia. By day, they bustle around the medieval streets, almost oblivious now to the newsstands trumpeting the latest claim about the murder investigation.
By night, they hang out at La Tana dell'Orso, close to the University for Stranieri (foreigners). The owner, Esteban Garcia Pascual, remembers Meredith Kercher as a regular customer with dark good looks, "a really nice, smiling girl coming here for live music and drinking with her English girlfriends".
He says many English girls come to La Tana dell'Orso because they find a "big sister" in his English wife, who was once herself an Erasmus student. (He is an Argentinian with an Italian mother).
He rejects as "disgusting" claims in the Italian press that student bars were serving a drink called "Bloody Mez" in the aftermath of the murder.
The concoction -- almost certainly a tasteless urban myth -- was said to be Meredith Kercher's favourite tipple of vodka, lemon and Coca-Cola.
Meanwhile, an Italian student says she has been reflecting recently on the risks she may have taken during her own Erasmus year in Spain.
"You're enthusiastic. You make friends with everyone, you go to every party. But really you have to exercise caution, and choose your friends carefully."
The fate of Meredith Kercher, who died in this beautiful place far from home, has frightened every parent with a child studying abroad.
Students returning home this Christmas break will be held a little closer by mothers and fathers grateful that they can only imagine the dark suffering of Meredith Kercher's parents.