Patient Zero is the main villain in the science fiction fantasy movie 51.
Patient Zero was originally an unidentified alien who crash landed on planet Earth. It was found by the US military and taken directly to Area 51 where it became a frequent test subject. The base's scientists classified the alien as Patient Zero.
Overtime, the scientists discovered that Patient Zero could mimic the appearances and mannerisms of other people. They decided to nickname the test subject as "Morpher". It was contained for twenty-five years along with other aliens. It was rendered dormant by exposure to experimental drugs and upbeat music on a daily basis.
Patient Zero undergoes a top-secret experiment while a private tour of Area 51 is held. It decides to escape containment. It begins by pretending to be dead in order to deceive a scientist and two soldiers. Patient Zero touches the scientist and copies his entire appearance. The soldiers have trouble telling the difference and shoot the wrong person. Patient Zero performs the same strategy on the first soldier.
He is accidentally shot by the second soldier who is also confused by the ambiguity. Patient Zero kills the second soldier before leaving its cell. Other aliens are released from their cells before they kill other soldiers. A security camera operator is murdered by Patient Zero while it is still disguised as a scientist. Meanwhile, the tour is immediately canceled and the entire facility is placed under lock down. This event doesn't stop Patient Zero who continues to murder more humans. Patient Zero then disguises itself as a soldier and blends with the tour group. They are already aware of the outbreak and become suspicious. Each individual's retina is scanned for a reflection. The soldier reveals himself to be Patient Zero. The tour group is saved by a different alien who is friendly.
They are soon attacked by a another hostile alien while Patient Zero manages to escape. They also escape and find Patient Zero in the base's quarantine section. It observes a video of an autopsy and an alien's dead body. Angry, Patient Zero attacks them with a military assault rifle. It then retreats into a nearby air vent. The group and the friendly alien return to the surface level. However, one of the members reveals to be Patient Zero and it attempts to kill everyone. It is shot by the only soldier who survived the alien outbreak. Patient Zero dies and the survivors leave Area 51.