Arcane mark ward

Arcane mark ward was an abjuration spell used by the Red Wizards of Thay to protect their enclaves from intrusion without their knowledge.

Effects
This spell took ten minutes to cast and lasted a few days to many days, depending on the level of the caster. The spell covered a sphere with a radius of 25 ft (7.6 m) centered on a point. The effect of the spell was very similar to the alarm spell, except the trigger was a person or object that had previously been tagged with the caster's arcane mark. When such a person or object crossed the perimeter of the sphere in either direction, the caster was alerted by a mental touch that was noticeable without breaking concentration. If the caster was in a natural sleep state, he or she was awakened. The caster had to be within one mile (1.6 km) of the ward in order to receive the alarm.

Objects and creatures that were traveling in the Ethereal or Astral planes did not trip the ward unless they phased into the Material plane while inside the warded volume.

Components
In addition to verbal and somatic components, this spell required the same arcane focus as the alarm spell: a very thin silver wire and a tiny bell.