Seal of Saint Theophilus  is a sacred impression made by the saint's ring. The image of the seal is that of a dove, a harbinger of hope in Orthodox religion.
In the 980s, Saint Theophilus managed to seal the Four Horsemen of the Apocalypse into a Codex of Saint Theophilus utilizing red wax and an impression from his ring. Since then both items were regarded as great treasures and kept under guard at the Monastery of Saint Theophilus. Even after the Codex was lost, the ring remained in the monastery. 
In the 1980s, the Ghostbusters journeyed to the monastery to use the ring to seal the Four Horsemen once again. Peter Venkman ultimately used the ring when it fell to him.
- ↑ Father Yanos (2009). The Real Ghostbusters - "Apocalypse - - What, Now?" (1987) (DVD ts. 12:39-12:49). Time Life Entertainment. Yanos says: "According to the book, there is one hope for the world. The ghosts can be imprisoned again by the seal of Saint Theophilus."
- ↑ Father Yanos (2009). The Real Ghostbusters - "Apocalypse - - What, Now?" (1987) (DVD ts. 12:54-12:57). Time Life Entertainment. Yanos says: "The seal is kept safe at the Monastery in Greece."