From the publisher:
The Behind the Spells series continues with the darkness spell! This series examines those spells from the v3.5 SRD that are listed time and again on character sheets throughout gaming.
These are the spells which, if on your character's class list, will be taken as soon as possible and include such quintessential favorites as magic missile and fireball. Each pdf in this series examines the spellcaster who created the spell, one or more of the spell's hidden capabilities, and possible variants for the spell.
This issue includes two spell secrets, a new metamagic feat (Spell-shade) and a new spell (Cone of Shadows)!