After learning of the Codex of Saint Theophilus being sold at auction in New York City, Father Yanos took a flight from Greece hoping to procure the book and prevent the seal from being broken. He was too late and the Four Horsemen of the Apocalypse were freed. Yanos arrived at the Firehouse and informed the Ghostbusters about the Four Horsemen and their connection to the Codex.
Together, they took the next flight to Greece to use the Seal of Saint Theophilus to imprison the ghosts once again. While the Ghostbusters took the lift up to the Monastery, the Four Horsemen sabotaged it. The lift's fall was broken by Yanos. He survived with little injury and made it up to the Monastery and witnessed a surge in life after the Four Horsemen were sealed again.
- The look of Father Yanos looks to be a nod to the Father Merrin character from the The Exorcist franchise.
- Marsha Goodman (1986). Episode Call Sheet and SAG Report - "Apocalypse - - What, Now?" (1986).
- Edens, Mark & Edens, Michael (June 9, 1986). "The Real Ghostbusters: The Complete Collection" (2008), Volume Two, Disc Five, "Apocalypse - - What, Now?" Script, p. 21. Time Life.
- Father Yanos (2009). The Real Ghostbusters - "Apocalypse - - What, Now?" (1987) (DVD ts. 11:59-12:00). Time Life Entertainment. Yanos says: "My name is Father Yanos."
- Father Yanos (2009). The Real Ghostbusters - "Apocalypse - - What, Now?" (1987) (DVD ts. 12:04-12:06). Time Life Entertainment. Yanos says: "From the Monastery of Saint Theophilus."
- Edens, Mark and Edens, Michael (2009). The Real Ghostbusters Complete Collection Volume Two Disc Five, "Apocalypse -- What, Now?" p. 20. CPT Holdings, Inc.