Eye of Warning

You conjure forth a phantasmal sentry—a slender pillar 6 feet tall, topped with a floating, unblinking eye. The eye protects you from your enemies’ efforts to scry on you, watches over your camp, and cries out an alert if danger approaches.

Component Cost: 800 gp
Market Price: 4,200 gp
Key Skill: Arcana
Level: 14
Category: Warding
Time: 30 minutes
Duration: 24 hours (special)

This ritual works the same as Eye of Alarm.
    In addition, an eye of warning automatically detects any scrying sensor that appears or moves within 10 squares of it, treating the sensor as an intruder. Furthermore, the eye destroys the sensor immediately after warning you unless the creator of the scrying sensor succeeds on an Arcana check (DC 20 + your level). Wherever you are, you instantly know if the eye encounters a sensor. Each round the sensor remains within 10 squares of an eye, the eye attempts to destroy it again.
    Optional Focus: As with the Eye of Alarm ritual, you can extend the duration of this ritual indefinitely by keeping a focus in the vicinity. This ritual focus is a small, jeweled eye made of gold and ruby, worth 1,600 gp.

Published in Player's Handbook, page(s) 305.