This spell enables the caster to detect all undead creatures out to the limit of the spell. The area of effect extends in a path 10 feet wide and 60 feet long (plus 10 feet longer per level of the wizard), in the direction the caster is facing. Scanning a direction requires one round, and the caster must be motionless.
While the spell indicates direction, it does not give specific location or distance. It detects undead through walls and obstacles but is blocked by 1 foot of solid stone, 1 yard of wood or loose earth, or a thin coating of metal. The spell does not indicate the type of undead detected, only that undead are present.
The material component for this spell is a bit of earth from a grave.