Five years after the new balance with Trisolaris was established, Luo Ji visits a vast gravitational-wave antenna in northern China with Zhuang Yan and their daughter Xia Xia. The antenna, suspended above the ground, is both a technological monument and a sign of the new era. Because it sends continuous gravitational-wave emissions, water vapor gathers above it and creates a small green oasis in the surrounding desert.

As the family walks beneath the mirror-smooth cylinder, the visit becomes intimate rather than political. Xia Xia plays on the grass and tries to push the antenna, and Luo Ji jokingly says that with enough time she could move the Earth. Luo Ji and Zhuang Yan share a quiet moment that recalls their long, improbable history together and emphasizes that the peace Luo Ji created has made ordinary family life possible.

The scene changes when a sophon unfolds beside them and a Trisolaran begins speaking. The speaker says the visit is a protest against a claim in Luo Ji's recent speech: although Luo Ji was right that humanity's delayed recognition of the dark forest came from its capacity for love, he was wrong to suggest that humanity might be unique in possessing love. The Trisolaran explains that love also appeared on Trisolaris, but because it did not serve civilization's collective survival, it was suppressed before it could fully develop.

Luo Ji asks who is speaking, and the Trisolaran reveals that this is the same operator who transmitted the warning to Earth two and a half centuries earlier. Now near death after surviving in a dehydrated state, the operator says there may be seeds of love elsewhere in the universe as well, and those seeds should be encouraged to grow even if doing so involves risk. Luo Ji agrees and says he dreams that one day bright sunlight will shine into the dark forest. The chapter ends at sunset with Xia Xia unafraid of the coming dark because she knows the sun will rise again, turning the family's calm confidence into the book's final note of hope.