The World is Dying...
Different religions recall the feud differently. Some say the gods smote each other in a great war, other believe the capricious gods felt under appreciated, and so, locked themselves away. Still more believe a great trickster, a corruptor that is known by many names, sealed the gods away, accounts vary wildly as to why or how. Still others believe the Gods merely grew bored, and have abandoned our world to seek more interesting realms to play with.
The only thing that all religions can agree on is that the Gods have left us, and that the world is dying because of it.
It won't die during your generation, and unless you're an elf, your children may well never live to see it, but the world is crumbling. Suffocating, dying a slow cold death as the world of mortal wanes like a plant in winter without divine light. The cancer of entropy eating away at the edges of the system of our reality.
The key to saving the realm of mortals lies somewhere in The Valley of Ancients, a mist-shrouded valley, dotted with lost and forgotten temples. Some say the Valley of Ancients is the last place in the world where the Gods still walk. Others say the gods were imprisoned somewhere deep within the valley. Still others believe items of great power, catalysts that might spark the light to save mankind, can be found amid these ancient ruins and temples.
The only thing that every religion agrees on is the Great Wolf Guardian Lycia.
Some call her a scourge, some believe she was the beloved wife of the Moon God, once there were many who believe she was nothing more than an overgrown dire wolf, grown massive on travelers tales and rumors. 200 years ago, as his kingdom crumbled to famine and ruin around him a great king named Titus sent an army, hundreds of men at arms, a hundred lances of cavalry, to subdue the beast so he could claim the valley and it's secrets for his own. The army was slaughtered to a man, and rumors say the corpse of the fool king Titus lays at the back of Lycias lair to this day, a nameless corpse atop a pile of doomed men.
The great wolf has staked the entire valley as her territory, and she ruthlessly hunts down and kills any and all trespassers. This makes the valley a death trap, usually.
Every full moon, Lycia climbs to the summit of one mountains which pen in the great valley, and spends the night, along with most of her children howling in what many scholars and druids have reported to be a call of longing and mourning. No one is sure why Lycia calls to the full moon, but the "safest" time to enter the valley is during these brief windows, while she and most of her children are distracted. (safest, in this case, meaning the only time where the odds of dismemberment are below 90% and thus effectively the only time a sane man would ever dare venture into the valley)
This is not a fool proof plan however, as the weather must abide Lycias mood, and should the clouds conceal the moon and cut short her calling, she's been known to take her frustrations out on desperate, fleeing adventurers.