The novel follows high school senior Mara Carlyle and the world she now knows – where teenagers explode out of nowhere. While there does not appear to be a cause, the nation, as well as the FBI turn to her town for answers. As things turn to chaos, Mara and her friends band together to try and somehow make it to graduation whole.
Langford has a history of starring in young adult novel adaptations. While she is best known for playing Hannah Baker in the TV adaption of 13 Reasons Why by Jay Asher, she will also star in the upcoming movie Love, Simon, which is based off Simon vs. the Homo Sapiens Agenda by Becky Albertalli.
Spontaneous will be written and directed by Brian Duffield. Matt Kaplan and Max Siemers of Awesomeness Films will produce alongside of Nicki Cortese via Jurassic Party Productions.