The Mass That Remains #1018497

To stop a ship, a city must decide what it can lose.
Aster is approaching Ostro with thirty-one thousand eight hundred and forty people aboard. Reaching the port of Lume is not enough to save them: the ship must be slowed. Materials are needed to be transformed into plasma jets, which its magnetic sail receives and deflects to brake.
But those materials hold workshops, greenhouses and homes together. After an accident, completing the manoeuvre means dismantling what allows other communities to live. Every load has a cost, every delay narrows the possibilities. One hundred and thirteen days remain.
Mara Velsari must secure the cooperation of communities that remember the order she gave twenty-two years earlier. Meanwhile her son Elio chooses a life that is not hers to decide. On board, Captain Sira Nahal must hold together those who want to save everyone and those who believe it possible to save only some.
How much can you ask of someone to save someone else? Amid lost work, broken ties and irreversible decisions, the mass needed to stop a ship changes for ever the lives of those who give it up.