Gilgamesh is a 1976 Japanese manga series written and illustrated by Shotaro Ishinomori, adapted into a dark and apocalyptic anime series by Group TAC in 2003. The story is heavily influenced by the ancient Mesopotamian epic poem known as the Epic of Gilgamesh.
The story begins as the Tomb of Gilgamesh is discovered by a young scientist named Terumichi Madoka, causing the world's most recognized scientists to gather, initiating the Heaven's Gate project. When an unknown life form called Tear materializes in Delphys (a pit surrounding the tomb of Gilgamesh that seems to have no dimensions) and begins to contaminate embryos that around of it, the scientists decide to stop the project completely. However, Dr. Madoka breaches the guard around Delphys and comes into direct contact with Tear, causing an immense explosion that blocks out the sky with a mirror-like layer. This is considered an act of terrorism, as after the explosion, computers and wireless communications stopped working, and the planet fell into war and famine, causing the death of most of humanity.