The player also learns of the existence of the "Precursors", an alien race that came to this planet to research a bacteria called the "Kharaa". 4546B is under automated quarantine due to the bacteria escaping in an accident. The Quarantine Enforcement Platform shoots down ships that attempt to leave, land or enter orbit in order to stop the bacterium from spreading to other worlds. The player witnesses this happen when another ship, the Sunbeam, detects the Aurora’s distress signal. When the player attempts to deactivate the installation, it fails due to the player being "infected". In order to leave the planet, the player must locate the Precursors' base deep underground to find the Sea Emperor Leviathan. It has been keeping the life in the area alive by using small creatures known as "Peepers" to distribute small amounts of a degraded form of the cure. This keeps the planet's flora and fauna alive but it is insufficient to eradicate the plague. It asks the player to help it hatch its eggs because its young produce the cure in a purer form. Once the player hatches the eggs using a hatching enzyme received from the Sea Emperor Leviathan, the player is cured of the infection. They are then free to disable the Quarantine Enforcement Platform and construct a rocket to leave the planet, ending the game.