Lightfoot

(Spell Compendium, page 132, DnD 3.5)

Transmutation

Level: ; Assassin 1; Ranger 1
Components: V
Casting Time: 1 swift action
Range: Personal
Target: You
Duration: 1 round

You mutter the words of this short spell and dive down the hallway, dancing between the armed guards and out the gate.

You provoke no attacks of opportunity when moving.