Wall of Fog

By casting this spell, the wizard creates a billowing wall of misty vapors in any area within the spell range. The wall of fog obscures all sight, normal and infravision, beyond 2 feet. The caster may create less vapor if he wishes. The wall must be a roughly cubic or rectangular mass, at least 10 feet across in its smallest dimension. The misty vapors persist for three or more rounds. Their duration can be halved by a moderate wind, and they can be blown away by a strong wind.

The material component is a pinch of split dried peas.