Three men were buried into the womb of a bog a long time ago. They all ended up there, not because they were thieves or murderers, but because they were different. They devoted their lives either for professionalism, being one with the nature or just to help those in need.
Tista, the priestess of the bog, buried these misjudged gentlemen after their death to the bog to preserve them for a later use.
Now these corpses have risen from their forever sleep to take care of some unfinished (music) business on the face of the earth.
