Melinoe was a goddess of ghosts. She wandered the earth followed a ghosts and brought madness and nightmares to men. Melinoe was the daughter of Persephone, who was visited by Zeus disguised as her husband Hades. In some version Hades is described as her father. In Greek mythology, Melinoe is described as being half dark and half light because she was daughter of Zeus(light) and Persephone(dark) or Hades(dark) and Persephone(light).
Melinoe had the power to turn any mortal insane with her ghostly phantoms. She leads the restless spirits of the underworld to haunt the living during the night. This is said to be the reason why dogs howl at night.
Zeus and Persephone