Spirit Net (Arcana/Necromancy)
Level: Mage 2
Mana: 4. Base Success: 90%.
  Mystically inscribes open surfaces and wall edges within a volumetric 'blast' of radius 40 feet (4 squares) with warding runes. The runes prevent incorporeal creatures and summoned creatures from passing. Such creatures can still attack and cast spells. The runes appear simultaneously but fade and disappear at a slightly staggered rate.