Mastery of the Mists

(Player's Guide to Eberron, page 126, DnD 3.5)

[General]

By learning of the intricate relationship between the Ethereal Plane and the Material Plane, you gain the ability to see and sometimes reach through the barrier between these two planes.

Prerequisite

Knowledge (the planes) 6 ranks, Spellcraft 12 ranks

Benefit

As a move action, you can see ethereal creatures and objects as if you were under the effect of a see invisibility spell for 1 round. (This ability doesn't let you see other invisible creatures or objects.) When you cast a spell on the Material Plane, you can attempt a caster level check (DC 15 + spell level) to target an ethereal creature or object you can see as if it weren't ethereal. Spells without a target entry (such as fireball) can't benefit from this ability. No more than one ethereal creature or object can be targeted with a spell in this manner, and you can't target ethereal and material creatures or objects with the same spell when using this ability.