The party eventually makes it back to the Killavullen cave and after destroying the remaining grimlocks, they find another portal. This one, they discover, operates via blood. The blood of its operator opens a portal.
They test it with grimlock blood, and it brings them back to the cave they’re already in. With Eddard’s blood, it takes them to the ruined Cordoba compound. For Ziegfried and Gareth, it’s to another cave. When they go through, they discover it’s a cave in Faerun, somewhere in the Sword Mountains near Neverwinter.
They discover a dead githzerai near the entrance before being attacked by a number of ghouls..