From publisher blurb:
Avalon takes a common spell and provides you with a number of alterations and additions to add excitement and useful options for your next adventure. Each issue of Avalon Spell Books will focus on a new spell, discussing different versions of the spell, providing different components that can be used to alter the way the spell works, and even adding feats and new magical items linked to the spell in question.
This month we have Mist Magic.
Obscuring mist and fog cloud spells have long been iconic examples of low-level magic powers, widely renowned for their ability to make a mess of the battlefield, turning combat into a game of hide-and-seek.
Many spellcasters still frown upon the clouds that hinder them as much as their opponents, choosing more direct affect spells to prepare. No surprise that divine spellcasters are sometimes found most heretically grumbling at the unavoidable obscuring mist spell in their domain spell lists.
Yet some curious researchers have delved deeper into the secrets of mists, finding ways to improve their eyesight, get new summonable monsters and shape cloud dwellings. They have found ways to do things, normally impossible at windier places with better view, where mist doesn't stay long enough.