Sixteen-year-old Sara Sanchez has seen her brother die fifteen times. He's drowned, burned to death, been shot by arrows, and stabbed. He's had his head chopped off, his eyes plucked out, and his skin flayed. But this time is going to be different - this time he's going to live. Sara's going to make sure of it - because Sara has a secret: she can travel through time.

Sara's been reliving the same year over and over in an attempt to save her younger brother's life. And Noah, the boy she loves, is always waiting for her in the future. She's supposed to be using time travel to save the planet from destruction by an alien invasion - but no matter how hard she and her friends try, one thing always stands in her way: with the death of her brother comes the end of the world. But maybe, just maybe, if she can save him, she can save them all...