Wren lives in the 23rd century where the Earth is on the brink of apocalypse due to overcrowding. Being the geeky, shy type, she's mystified when she gets picked to join an elite combat training ship, full of teenage cadets. They're fighting for control of Kepler - an earth-like planet, which has been chosen to alleviate the overcrowding on earth. Will Wren survive the 4-year trip or will the training kill her first?