Despite the crew's objection, Mal disguises Serenity as a Reaver ship and travels to Miranda. On the planet, the crew find all its colonists dead and a recording by the last surviving member of an Alliance survey team (Sarah Paulson). She explains that an experimental chemical designed to suppress aggression was added into Miranda's air. Most residents became so docile they stopped performing all activities of daily living and allowed themselves to die. A small portion of the population had the opposite reaction and became exceedingly aggressive and violent, turning into Reavers.