Travelling to, and from, Netherworld.

Apart from The Keeper, Nishka, The Agent and The Librarian, there is only one way in and out of Netherworld - and that is at the discretion of The Keeper.  The keeper opens gates between Netherworld and other planes to allow adventurers, and others, to travel between worlds.  However, there are more than one type of gate.

For adventurers leaving Netherworld, he opens a gate, then leaves it in place, but keyed to the people who left.  Adventurers can only return to Netherworld by that gate or, exceptionally, if the Keeper decides to bring them ‘home’ for his own purposes.  Asking the keeper for special dispensation, because you want to go shopping or to avoid a messy encounter, won’t work.

In special circumstances, the keeper opens a fixed gate that remains in place for multiple visits, although these are more heavily controlled and require a special key.  This key acts as a doorbell and alerts the keeper that someone wants to visit Netherworld, he then decides to activate the gate - or not.  The key could be anything, in one case it is a unique dance, in another a specific object must be used in a specific way.  Another type is operated by a touching a specific part of a tattoo, although the tattoo is also keyed to specific gates.

The third type of gate is the most common, although perhaps the least known.  The Keeper likes to people-watch, and his gaze wanders across the planes regularly.  He watches all sorts of things, but if notices an injustice, someone fleeing from attack, or persecution - he may decide to open a gate that brings them to Netherworld.  Some rescued characters decide to return home, others decide to stay in Netherworld -  and this has been the way that most of the general population of Netherworld arrived.