In the plague-ravaged city of Mercury, survival is a daily act of defiance. Ava is a street-smart addict living in crumbling tenement housing with five strangers she doesn't trust, and doesn't plan to. But desperation has a way of forging dangerous bonds. As a plague spreads rapidly, the six women volunteer for the Night Trials, a brutal monthly challenge that sends them deep into the mine on the outskirts of the city. There, they face living nightmares and uncover a truth far more terrifying than the disease itself. Their mission is impossible: travel back in time and stop the plague before it ever reaches Mercury. But when survival demands everything, Ava must choose between saving the city or the women who have become her family.