Fire of Entanglement

Evocation
Level: Paladin * 2
Components: V, S
Casting Time: 1 Swift Action
Range: special (see text)
Target: one creature
Duration: 1 round/level
Saving Throw: Reflex partial
Spell Resistance: yes
  The next creature you attack using your smite evil class ability is wreathed in flames that impede its movement.
  Until the end of the spell's duration, the target is Entangled.
  If the target starts its turn in a square adjacent to you, it is considered to be Entangled to an immobile Object (you) and cannot move. A target that saves against this spell is affected for only 1 round.