On August 21, 2015, Ayoub al-Khazzani, inspired by ISIS, boarded a train bound for Paris carrying a blade, a pistol and an AK-47 with enough ammunition to slaughter all 554 people on board.

Fortunately, a massacre was averted when three brave young American friends, Spencer Stone, Alek Skarlatos and Anthony Sadler, intervened.

Sitting in their carriage, they heard gunshots and glass breaking, a railway employee sprinted past, then a man appeared carrying an automatic rifle.

The three acted immediately, overcoming al-Khazzani and hog-tying him on the floor with the help of a British traveller. They paid a price, with Stone almost losing a thumb and an eye after grappling with gun-toting terrorist.

Text Publishing’s The 15:17 to Paris, is a real-life thriller depicting the moments that led up to, and the aftermath of, their incredible bravery.

In a bizarre twist of fate, Stone, a staff sergeant in the US Air Force, was near-fatally stabbed in a street scuffle in Sacramento, California a month and a half later.

Stone, who is not being investigated for wrongdoing over the altercation, can’t say too much about the experience as he has yet to testify.

Suffice to say, a knife was plunged into his chest, puncturing his heart, and he almost died during life-saving surgery.

“I literally turned and said, ‘are you kidding me….. again?” Stone tells The New Daily.

The book describes the experiences of the three in heart-stopping detail and is interwoven with their family histories, the story of their friendship and the experience of their subsequent celebrity.

Stone is philosophical and positive about it all. The injuries he sustained are, “small potatoes compared to what could have happened. Just the fact that nobody died was the best thing”.

The book, co-written by the three with journalist Jeffrey E. Stern, has a great deal of humanity, even putting into context al-Khazzani’s story.

It also describes some witty moments; perhaps none more so than when President Obama spoke on speaker phone with the three childhood friends while they were still holed up in France. He pointed out that his class reunions usually don’t end with him tackling terrorists.

Stone, 24, finishes his service in November this year. He has ambitions to go back to school and study international security and conflict resolution, something you could say he has first-hand experience in.

“Other cultures really interest me and I like dealing with people that come from different parts of the world,” he said.

The media storm following their brave act had some high points from Stone’s perspective. He got to hang out with former basketball player Kobe Bryant and had dinner with Skarlatos and Sadler at actor and former Californian Governor Arnold Schwarzenegger’s home.

But Stone’s feet are still firmly on the ground. Not only are the three friends bonded for life, he says his family relationships are even tighter.

“Going to New York for the first time with my mom, brother and sister, I had this moment when I realised this is the first time we’ve all been on plane together going anywhere. That was a really cool experience.”

While the Paris trip, of course, didn’t quite work out the way they planned, they did get an unexpected upgrade to the American Ambassador’s official residence in the city.

Now Stone says his mum understandably panics every time he heads out on the town, but the attack hasn’t put him off travelling.

“I always say you can’t live your life in a bubble. If I was supposed to be dead, I’d be dead by now,” he reasons.

“I kind of just leave it in God’s hands. I’m just living my life, day by day, having fun. If something happens I’ll deal with it as best I can, if not, then I guess it’s my time to go.”