Limbo is a prison-like dimension used by the primal god Proteus to hold the Ghostbusters indefinitely.
Proteus manifested in New York City and influenced a surge in spectral activity. Eventually, he attacked the Ghostbusters and shot them with a beam attack. The blast transported the Ghostbusters to Limbo. Proteus could then view Limbo from one of the mirrors in his boardroom located on the 13th Floor of the Erie. Janine Melnitz shattered the mirror with a Proton Stream and freed the Ghostbusters. This also had the effect of weakening Proteus.
- IDW Comics
- Proteus (2015). IDW Comics- "Ghostbusters: Get Real Issue #1" (2015) (Comic p.8). Proteus says: "Instead of being transported to the nexus I chose, the Ghostbusters were lost."
- Icon Ghost (2015). IDW Comics- "Ghostbusters: Get Real Issue #2" (2015) (Comic p.1). Icon Ghost says: "Last time we checked in, The Real Ghostbusters were zapped by the Elder God Proteus, who had intended to send them into a cage of his own design for all eternity!"