When 17 year old Liv Larson and her brother are sent to separate foster homes, she becomes content with her isolation and dedicates her every breath to getting him back. After months of solitude and anti-social behavior, Liv's best friend Riley drags her to a Rooftop Party to view Icarus (the once in a lifetime solar flare) where Liv finds herself inexplicably drawn to Zander James, the mysterious boy with the crooked smile.

For a few hours, Liv's troubles finally feel a bit less overwhelming-that is until what should have been a small flare erupts into a massive solar storm forcing them all to seek shelter in the school's basement. Cut off from the rest of the world and with no signs of rescue, fear and paranoia set in and battle lines are drawn, dividing their ranks. What is left the group must embark on a perilous journey to save one of their own and find their families... but, something sinister awaits them in the shadows and it's undeniably connected to Liv.

Can Liv keep her promise to reunite with her brother? What are she and her friends willing to do to survive? Will their bravery and determination be enough to save them all from a rogue government, a terrifying virus, and the things that go bump in the night…Or was Icarus, indeed, The Killshot?