Doctor

A ship's physician aboard an interstellar liner monitors passengers and cargo while an emergent microscopic threat on a distant planet multiplies by autocatalysis. Scientists identify the new agent as chlorophage, a self-replicating molecule that converts surrounding matter into copies of itself and imperils planetary ecosystems. The doctor scrutinizes arrivals at a spaceport, aware that a single infected passenger could trigger quarantine measures that would strand or doom whole populations. The story follows the tensions of medical vigilance and administrative procedure aboard the liner as anxious families embark and officials confront the moral and logistical challenges of containing a pandemic in space.