Thieves' Night Comet

"Though this is the quietest night of all, few will find sleep"

A soft wind from the East wafts through forest leaves, which flutter and whisper like ocean waves. Moonlight glances off of the topmost branches, shimmering like sea foam. Above, clouds, thin and ethereal, drift onward towards the sea, revealing constellations which festoon the night sky. Without warning, a streak of light crosses the sky. It passes from the North to the South, and as it flies, silently slicing apart the night, it passes through one, two, three stars in a line. Each of the three stars shines momentarily brighter, and thin white lines connect the points like a spider's web.
The web in the sky pulses once, as the comet passes on to some other unknown corner of the universe, and the wind falls silent. No more sighing of ocean waves, no more buffeting of sails. Around the world, thieves are awakened by the quiet. Guards double their watch and cling tight to their spears. Astronomers run to their telescopes to examine the rune of silence that the comet has drawn in the sky. Though this is the quietest night of all, few will find sleep.

Overview

The Thieves' night Comet is a celestial body which rarely passes over the night sky of Menorien. When it does, though, it attracts much attention, from scholars and commoners alike for this reason: The stars it connects in it's usual path are part of a constellation which (when these particular stars are connected) draws out a rune of silence. For 2 hours, 16 minutes and 53 seconds to 6 hours, 35 minutes and 4 seconds after the comet passes over, provided that it is still night, the world is plunged into silence.
This night has many uses for astronomers, who study it's path, and thieves, hence it's name. However, for guards and spellcasters, it is more of a curse. In most towns, the only way for guards to raise the alarm is to call out, which now is not possible. Similarly, magic users often rely on incantations to cast their spells, which doesn't work in these circumstances (There are ways to overcome these limitations, however - see sidebar). Lastly, many raiders and monsters use the cover of silence to attack settlements in civilised lands, which has led to many conflicts in the past.

Theory

The reason behind the comet's path, or indeed the exact nature of it's power is subject to much discussion amongst astronomers and magi. Through ongoing research by scholars in Lenthall and The City of Keelford, the magical aura of the comet has been detected (as expected (Ha ha! - rhymes)) to be strong abjuration magic. However, there are also less potent auras of conjuration and necromancy present. These last two auras have been the source of much debate. Some of the foremost schools of thought theorise that the soul of a disgraced deity of silence was bound to the comet, and the magical silence represents that God's last amount of influence on the world. This explains the necromancy. The conjuration might be caused by the creation of the other lines connecting the stars, though what these are made of is still unknown. Other scholars suspect that the comet was a result of an ancient magical experiment or disaster, as told in early mythology meant to warn casters of meddling with forces beyond their understanding. This theory would suggest that these tales have some truth to them. Some say that this is simply a weird phenomenon brought about by chance.

Mitigation

As mentioned in the main article, this night, and magical silence in general, can be difficult for spellcasters. Over the years, magi have tried many ways to mitigate the effects of this magic, two of which are detailed below.

Wands and Staves

Many magical wands and staves have properties which allow them to cast spells without any verbal, somatic, or material components. Although this allows for casting in silence, it vastly limits the spells availible to the caster, leading to many seeking out a better solution.

Anti-Silence Field Generator

An Anti-Silence Field Generator (TM) is a very rare magical item which allows a caster to use verbal spell components in a small field (usually only around the caster's head) whilst in magical silence. Their methods of manufacture are kept a close secret by the Sorcerer Egnon, a mage notorious for his inability to create catchy names for products. It is difficult to find out the inner workings of the device, as Egnon places booby traps inside all of his items to stop his competitors from gaining the upper hand, but many magi suspect that the generators bend the abjuration energy of the silence field to create a breach through which sound can travel.