Ghostwalk

Move through solid objects in any direction by the amount of Movement spent, provided that the solid object is not silver or cold iron (iron that has been worked without a fire.)

The inside of solid objects count as Airless Zones.

If your movement is reduced to 0 while inside an object, you remain fixed in position. Losing the ability to perform this type of Movement while inside a solid object shunts you out into the nearest empty space and deals Ethereal/Blunt Damage equal to the number of Units that got you there.