Wondrous Item

Uncommon

This scroll is wound around a wooden dowel with owl faces on either end. When you use an action to read this scroll, choose a trigger for the scroll, centered on a point you can see within 30 feet of you, as well as up to five pieces of information to be recorded when that circumstance occurs. An invisible sensor appears at that point.
 The trigger can be as general or as detailed as you like, though it must be based on visual or audible conditions that occur within 30 feet of the point. For example, the trigger could be when a person that's at least five feet tall walks past the point in a northward direction, or if a creature says the word "Hello" nearby it.
 Whenever that circumstance occurs, the scroll unfurls slightly and magically scribes the specified pieces of information onto one line. For example, the scroll can record a triggering creature's color, apparent age, if it's visibly armed, its travel speed, and so on. Alternatively, it can track how many purchases are made in a shop, or the amount of coin that changes hands at a tavern. Or, if the trigger for the scroll is an audible one, the scroll can record what language the triggering creature is speaking.
  The scroll can't determine information not immediately apparent, such as a creature's name. The scroll has 60 inches of parchment, and each added line takes up 1 inch of it. When the last of parchment has been used in this way, the effect ends and the scroll loses its magic, although any information recorded on the parchment remains.
  A creature that can see the sensor (such as a creature benefiting from see invisibility or truesight) sees a watchful owl. The sensor is considered to have a passive Wisdom (Percep- tion) score of 15 for the purposes of detecting a triggering creature or effect.