Humanity went to Venus to save Earth. It never asked who already lived there. In 2062, climate scientist Celina Andrade arrives aboard Vespera Station to certify the Lattice: a flock of self-replicating machines designed to prove that humanity can alter a planet’s climate. If the demonstration succeeds, four million machines will be deployed, and a drowning Earth may finally gain the time it desperately needs. The test begins perfectly. Then the clouds answer. Beneath Vespera lies an intelligence unlike anything humanity imagined: an ancient civilization living within the deep atmosphere, communicating through vast patterns of light, chemistry, and song. As Cel and her crew struggle to understand their planetary neighbors, they uncover a devastating truth. Every successful step toward saving Earth is slowly destroying the inhabited world below them. And the system they were promised could stop the machines may never have worked at all. With Earth preparing to ratify the largest climate-engineering project in history, evidence disappearing into sealed channels, and loyalties aboard Vespera beginning to fracture, Cel must decide what she is willing to sacrifice for the truth. To make humanity listen, she may have to expose the lie that built her career—and commit an act that history will remember as first contact, mutiny, or both. Two inhabited worlds. One machine. No solution without a cost. Sister Planet is an emotionally charged first-contact novel of scientific discovery, institutional betrayal, planetary survival, and the dangerous moment when an environment becomes a neighbor.
