Six young criminals break into hidden catacombs and attempt to steal jewels, but some inhabitants are guarding the precious belongings. After being trapped in this dark maze of crypts, the group tries to escape alive.

In Moscow, the priest Owen hires a team to guide him in the underworld to find his friend Sergei that is missing while researching the legend about the existence of demons and an entrance to hell beneath the city.

When a team of explorers ventures into the catacombs that lie beneath the streets of Paris, they uncover the dark secret that lies within this city of the dead.