Level: Cleric 8, Sorcerer 8, Wizard 8
Components: V, S, DF
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Effect: A straight wall whose area is up to one 10-ft. square/level
Duration: 1 minute/level
Saving Throw: None
Spell Resistance: No
You cast the spell and a translucent wall springs up, its shimmering field pulsing with strong, malignant shades than spin and twist into each other.
This spell creates a transparent, permeable barrier. Anyone passing through it becomes the target of a greater dispel magic effect at your caster level. A summoned creature targeted in this way can be dispelled by the effect.
A wall of greater dispel magic cannot be seen or felt by ordinary means, or even with a see invisibility spell. Detect magic indicates the presence of the effect, and true seeing reveals its presence.
Source: Spell Compendium, page 234.