Sentry of Helm

This spell was created by the priests of Helm to aid in guard duty while most members of a group of travelers in the wild are sleeping. Like the lst-level wizard spell unseen servant, this spell creates an invisible, mindless, and shapeless force. This force cannot fight and, unlike an unseen servant, it cannot affect its physical surrounding except as indicated below.

The priest casts this spell by walking the perimeter of the area of effect sprinkling pinches of sand every few feet and then returning to the center of the area of effect. Once the spellcasting is completed, the shadowy sentry stands guard in the center of the area of effect and the caster immediately falls asleep.

If any visible object over 1 foot in length, width, or height which was not present during the casting of the spell enters the area of effect while the spell is in operation or if the spell is about to end, the shadowy force silently shakes the caster awake. When the caster awakes, the priest is wide awake and aware that something has triggered the sentry or that the spell has ended. The spell then immediately expires.

A visible object must be an object that a guard could have perceived with normal vision if she or he had been awake and on guard duty. Visible objects cannot be invisible, hiding in shadows, or hidden behind walls, trees, or earth.

If this spell is cast by a priest of 5th level or higher, the sentry of Helm also has 60-foot infravision in addition to normal sight, and what is visible to it includes beings seen with that faculty.

The material component of this spell is the priest's holy symbol and a small bag of fine sand.