It was a blistering cold night when Maura Murray disappeared.

The University of Massachusetts student was driving her black Saturn through the winding roads of the White Mountains of New Hampshire, when she lost control of her car and ploughed into a snowbank.

Moments later, a local bus driver named Butch Atwood came upon the scene. Butch asked a shaking Maura whether she needed any help.

Panicking, Maura asked Butch not to call the authorities as she had already called Triple A.

No Footprints: The Mysterious Disappearance Of Maura Murray. Post continues after podcast.

The bus driver then drove the few hundred metres down the road to his house, certain that Maura was lying to him. As a local he knew there was no cell phone signal in the area and there was no way Maura could have called for help.

Once he parked in his driveway, Butch looked back at the scene to see Maura still at her car. He then went into the house and asked his wife to call 911.

When they looked out the window a few minutes later, Maura was gone.

There has never been a credible sighting of her since.

Maura’s remains have never been found and she hasn’t accessed her bank accounts or reached out to her family or friends since she vanished.

In the 15 years since her disappearance, Maura’s case has become the obsession of many amatuer sleuths.

Blogs, reddit threads, two podcasts, and a book, have all been dedicated to the search for answers in the disappearance of the 21-year-old.

Some have referred to Maura as the original Gone Girl. She has been painted as an All-American girl next door, who was hiding dark secrets and a troubling past, behind her perfect grades and track star exterior.

But none have been more obsessed with the case then James Renner, an Ohio-based writer who spent years investigating Maura’s disappearance and penning a book called True Crime Addict: How I Lost Myself in the Mysterious Disappearance of Maura Murray.

During his investigation, Renner discovered Maura was asked to leave the prestigious West Point Academy a couple of years before her disappearance, after she stole makeup from one of the stores on campus.

Maura then transferred to UMass and began studying nursing. But it wasn't long until Maura was in trouble again. According to Renner, Maura had recorded the numbers off another student's credit card and used them to buy food. She was charged by the local police and put on probation.

From there, Maura's case becomes even more baffling.

Three nights before she disappeared, a student at UMass was injured in a hit and run accident. Some people have theorised that Maura could have been driving the car, but there has never been any proof of this.

Later that night, Maura became distressed at her job manning one of the college's reception desks, and was escorted home by her supervisor. When her supervisor asked Maura what was wrong, all she could reply was 'my sister'. Maura's sister has said there was nothing wrong with her at this time.

Two days before she went missing, Maura's father Fred withdrew $4000 from eight different ATMs. He then travelled to UMass to visit Maura and they went looking for another second hand car for her. They never bought a car. Later that night, Maura crashed Fred's car on campus while driving home from a party.

On the day of her disappearance, Maura emailed her college professors and told them there had been a death in the family. There hadn't been a death.

She then started researching cabins in the White Mountains, before packing some belongings into her car and driving down Interstate 91.

We don't where Maura was travelling to or what she was planning. But later that night she would crash her car and then simply vanish.

There are many conflicting theories about what happened to Maura. Here are the most credible:

Maura was abducted by an opportunistic killer.

Many believe an opportunistic murderer - or a serial killer - snatched Maura in the mere minutes between when Butch Atwood last laid eyes on her and when she disappeared.

The theory goes that a vehicle stopped in the middle of the road - under the guise of offering Maura help - then the person or persons dragged her into the car and drove off before anyone noticed.

Although there have been several 'persons of interest' in Maura's disappearance over the years, no one has ever been charged or seriously investigated.

Maura ended her own life.

Some believe Maura drove into the White Mountains that night to end her own life.

The people who believe this theory think that after she crashed her car, Maura simply walked into the mountains and ended her own life.

While Maura was dealing with a lot of issues back home, her body has never been found.

Maura started a new life in Canada.

For years, James Renner believed that Maura had left the country and started a new life in Canada.

At the end of his book, Renner alleged that Maura's longterm boyfriend, Bill, had been abusive towards her. He believed that when Maura discovered she was pregnant with Bill's baby she hatched a plan to run away to Canada to start a new life.

Renner believed Maura had used an underground secret system of women to leave the country.

There has never been a credible sighting of Maura in Canada and she's never touched her bank accounts or reached out to her friends and family.

Maura wandered off into the woods and died of exposure.

A lot of people simple believe Maura wandered off into the woods that night and died of exposure.

It was snowing the night the 21-year-old disappeared and the White Mountains are quite treacherous.

However, they've been extensive searches of the area over the last 15 years and Maura's remains have never been found. The searches also haven't uncovered any proof that she had wandered into the White Mountains in the first place.

You can hear more about Maura's disappearance on this week's episode of True Crime Conversations.