Tulrun's tracer

Tulrun's tracer was a alteration/divination spell that created a luminescent pathway following the given route a particular person or creature has traveled.

Effects
Upon casting this spell, where the caster verbally described a specific being, an illuminated path appeared 10' (3 m) in front of them. This line of light continued at a rate of 10' per second, further revealing the directed the person or creature traveled. The tracer only illuminated the path they walked, ran or otherwise traveled by foot or any distance they covered while riding upon a living mount. It stopped its revelations as soon as it reached an area whereupon the subject teleported, spanned a gap or batter greater than 15' (4.6 m) or traveled to another plane of existence or traveled by any other means of conveyance or somehow took flight.

The path laid out by the tracer came to an end when duration of the spell ended or it reached a location where the target creature began to travel by some other means. If the latter was the case, the caster received a clear mental image of how the target altered their movement, and in the case of teleportation or traveling to another plane, became aware of the destination.

The tracer itself was intangible, could not be physically altered by passers-by or natural, physical occurrences such as wind or shifting of the ground. It was immune to the effects of less-powerful spells such as pass without trace, but portions of the illuminated pathway could be dispelled or concealed by other spells such as continual darkness.

Casting
In addition to verbal and somatic components, this spell required a pinch of phosphorus or a living plant or creature that emitted a natural glow.

History
This spell was developed by the great Uthgardt archmage Tulrun, sometime after he gained admittance into the magical academy known as the Incanistaeum, within the ancient city of Myth Drannor. The specifications of Tulrun's tracer were compiled within the Wizards' Workbook, a magical tome that was compiled by Mentor Wintercloak one of the academy's Seven Wizards.