A mishap while trapping Fenrir, a Norse wolf demon with icy breath, leaves Slimer accidentally trapped inside the Ecto-dimension of the Ghostbuster's Containment Unit. Now incarcerated along with all of the ghosts he helped capture, Slimer is made to pay for his "crimes." Donning a protective suit, Eduardo enters the ghost-plane to rescue Slimer while the other Ghostbusters try to stop Fenrir before it can bring about Ragnarok.
—Anonymous