Break on through to the other side!
The Gauntlet is the barrier between the material world and the Spirit World (also known as the Umbra, Tellurian, Shadowlands, Wraithlands, or Hyperspace). Wraiths know the Gauntlet as the Shroud.
The Gauntlet has waxed and waned over the centuries, in a constant flux depending on location and supernatural activity in the area, but has become much thinner everywhere since Gehenna, now that most unawakened humans know that magick and supernatural creatures exist. The Gauntlet is thinner in places like haunted graveyards or the wilderness, and thicker in places such as laboratories and shopping malls. The relative strength of the Gauntlet at any given location determines the ease with which one can cross it.
Crossing the Gauntlet[]
Werecreatures have a natural ability to "step sideways" through the Gauntlet into the Umbra, although reflective surfaces, polished silver, a quiet pool of water, and especially mirrors make stepping sideways easier.
Mages (especially Spirit Mages) with a sufficient mastery of magic can also cross through the Gauntlet.
More powerful Vampires can cross through the Gauntlet, and after Gehenna drove Vampires even more underground than they were before, many of them fled to the Wraithlands version of Enoch.
Unawakened humans can only do it with the aid of powerful technomagical devices such as gravity drives that can open a jump point to hyperspace.