Samhain was an ancient Celtic pagan festival marking the end of the harvest season and the beginning of winter — the darker half of the year.

Celebrated on November 1st, with festivities beginning on the evening of October 31st, it was considered the Celtic new year.

The Celts believed that on this night, the boundary between the worlds of the living and the dead became blurred. The ghosts of the dead returned to earth.

People would light sacred bonfires and wear costumes to ward off wandering spirits. It was a time for stock-taking, animal sacrifice, and communion with the dead.

In the 8th century, Pope Gregory III designated November 1st as All Saints Day, incorporating some traditions of Samhain. The preceding evening became known as All Hallows Eve.

Eventually, Halloween.

The veil is thinnest on this night. The dead walk among us. And some doors, once opened, cannot be closed.