You and up to 5 creatures that you touch are transported along a coiling path of shadowstuff to the edge of the Material Plane where it borders the Shadowfell.  While on this quasi-real path, a creature's walking speed is ten times faster, they are not affected by difficult terrain, and they can walk over water as if it were a solid surface Creatures affected by this spell cannot make out details on the Material Plane, but can get a rough idea of exactly where they are from visual landmarks. 

When this spell ends, every creature affected by the spell is immediately returned to the Material Plane wherever they have managed to travel to.

You cannot cast this spell in bright light, and it has no effect on a plane other than the Material Plane.  If a target of the spell is not willing to be transported, they can make a Charisma saving throw to avoid the effect.