You create a giant web of thick magical strands that hangs in midair, trapping those within it.

Daily   ✦     Arcane, Implement, Zone
Standard Action      Area burst 2 within 20 squares

Target: Each creature in the burst

Attack: Intelligence vs. Reflex

Hit: The target is immobilized (save ends).

Effect: The burst creates a zone of difficult terrain that lasts until the end of the encounter. Any creature that ends its movement in the zone is immobilized (save ends).

Update (1/24/2012)
Updated in Class Compendium.

Published in Player's Handbook, page(s) 161, Class Compendium.