Mere minutes from landing on Enceladus, sixth largest satellite of Saturn, a massive explosion shakes the Musk Venture, causing the exploration ship to veer off course and crash into the "ice shell" moon's sea. Out of forty, five survive, but they will not long survive unless they reach Supply Cache Alpha, where stores were deposited a year earlier by a robotic probe. Between them and safety lies a world filled with unknown perils, but the greatest threat to their survival might be themselves.