 Complete the following phrase:  Shortly after the foiling of the 2015 Thalys train attack earlier that year, Sadler made an appearance on The Tonight Show Starring Jimmy Fallon with host Jimmy Fallon in September 2015, discussing his role in disarming the gunman. Months later in 2016, Sadler, Alek Skarlatos and Spencer Stone started working on a memoir, titled The 15:17 to Paris, detailing the events of the train attack. Perseus Books Group, which published the book, described the memoir as the gripping true story of a terrorist attack that would have killed more than 500 people if not for their actions, but it is also the story of three American boys, their friendship, and the values we hold dear. David Steinberger, president and chief executive of Perseus Books Group, said that he was confident that this is going to be a film. Its extremely cinematic, and theres a lot of interest in the movie. He further stated, based on the material, that this was going to be an important book and one that readers were really going to respond to. The memoir was made available to the public on August 23, 2016, almost a year after the 