On 21 August 2015, Ayoub al-Khazzani boarded a train in Brussels bound for Paris. Khazzani's mission was clear- he had an AK-47, a pistol, a box cutter, and enough ammunition to obliterate the 554 passengers on the crowded train. But as he began to execute his plan, he encountered an unstoppable line of defence- three American friends.

The 15-17 to Paris is a gripping account of the foiled attack by the three men who lived it - Anthony Sadler, Alek Skarlatos and Spencer Stone. It is also the story of what compelled three lifelong friends to run towards danger instead of from it - towards humanity, not away from terror.