In the myths of Greek legends, when a person died, his soul would then wake up near the shores of styx. If the deceased soul had a small coin called obulus with them, then a single boat would appear in front of them. And a ferryman would take them across the river.
This coin wasn't something extraordinary, unique, or karma rule based currency like other religions _ it was a normal coin placed in the mouth, or eyes, or chest of the deceased during the burial rights. Usually parents of family members do this easily as it costs nothing.
But if one had no coin to speak of, his soul would then forever wander the shores of styx. They will never be able to cross the realm of living, and over time turn into vengeful spirits, wraiths, or ghosts.
