Beneath The Rising by Premee Mohamed

Years after a youthful experiment by a tight-knit group of aspiring scientists accidentally unleashed an impossible, world-consuming force, two of them are hauled back into a desperate attempt to stop the slow, relentless unmaking that is beginning to return. The story follows their tense reunion and the unraveling of memory, responsibility, and identity as they race to understand the cosmic threat they helped create, confront the betrayals and trauma of their past, and make terrible choices to try to avert an apocalypse—blending clinical scientific detail with mounting, uncanny dread.