District 9

The film opens with a documentary-style series of interviews that introduce the situation. Twenty years before, an alien ship is seen coming towards Earth and arrives above Johannesburg, South Africa. It hovers above the city for three months without any contact; eventually humans take the initiative and cut into the ship. They discover a large group of aliens who are malnourished and sick. The aliens are later assessed as apparently being all "workers", with their leadership mysteriously missing (it is hypothesized that a plague may have wiped out all of the leadership-caste). Grainy footage shows part of the ship (supposed to be a command module) falling to Earth, but nobody has been able to find it, leaving the ship inoperable.