FOR most of us, the idea of being held hostage by an armed killer is the stuff of total nightmares. But for Ashley Smith — who was a 26-year-old widow, struggling with drug addiction on the night she was held captive back in 2005 — this very experience turned out to be a blessing in disguise, changing her life for the better.

Brian Nichols was on trial for rape when he escaped from an Atlanta courthouse, killing four people before breaking into Smith's home. Incredibly, after seven hellish hours, he decided to let her go.

The remarkable story has now been turned into a film called Captive, starring David Oyelowo as Nichols and Fantastic Four actress Kate Mara as Smith.

Here, Smith recalls the emotions she experienced that fateful night, and how sharing the story has helped her move forward.

Ashley Smith had married at a young age, but after only a couple of years, her husband was murdered by a drug dealer, and she fell into methamphetamine addiction.

"I had a child with my husband, but due to the drugs and the lifestyle I was living, I lost custody of her," says Smith, who's now in her mid-30s. "My life at the time was a big mess," she admits. "I was going back and forth between God and drugs."

In the middle of her recovery process, she received a copy of pastor Rick Warren's The Purpose Driven Life, one of the bestselling, non-fiction books of all time. Little did she know that the book would eventually play a key role, when an "unlikely angel" arrived in the form of Brian Nichols.

On March 11, 2005, Nichols, whose son had just been born a few days earlier, was scheduled to begin the third day of his trial for rape charges, at a courthouse in Atlanta. While changing his clothes, he assaulted the sheriff's deputy watching him, stole her gun, and knocked her unconscious before going on the run. He went on to shoot four people, before driving to another town and forcing his way into Smith's apartment.

She didn't recognise him at first. It was only after Nichols asked her whether she'd watched the news that day that it dawned on her who he was. "I thought I was going to die," Smith recalls.

When Nichols asked if she had any drugs, Smith was forced to reveal the crystal meth she was keeping in her house. "He asked me if I wanted to do the meth with him, which ended up becoming the turning point in my life."

Alone with an armed killer who believed he had no way out, Smith made the choice to read aloud from The Purpose Driven Life.

"On the front of that book, it says, 'What On Earth Am I Here For?' That question was very important to me and something that I needed an answer in my life for," she says.

She'd only started reading the book a month before, and explains that she saw it as a tool in a "kind of spiritual warfare".

"Having been raised in a Christian family and knowing the bad path that I was on, I always felt there was a battle between good and evil going on in me, and I knew I had to take that on in my life. And that same battle was going on in Brian."

Her faith paid off and Smith's decision to read to Nichols led to him making some remarkable decisions too.

She said: "When I walked out of my door, I felt like a totally different person, and that's what I've tried to do since then, just change my life."

Smith acknowledges that Captive might not be well received by everybody, due to its almost sympathetic view of Nichols, but insists: "The film is a good depiction of what happened. It stays true to mine and Brian's emotions and how we were feeling at the time."

Since the ordeal 10 years ago, Smith has remarried and has three children. As well as working as a CT/X-ray technician in a local hospital, she also dedicates a lot of her time to public speaking, sharing the remarkable story of how her life was turned around. "It's not difficult, but quite emotional reliving the story. It allows me to remember where I came from," she says.

She has had no contact with Nichols since the event, yet has lately considered sending him a letter.

"I was a widow, drug addict mum and I'm the one that lived, as opposed to four well respected people in the community. It was very difficult for me to understand why — why did God choose me?"

Captive is released in cinemas tomorrow.