The River of Fate

Below the jewel filled night sky, somewhere in the world, the last vestiges of a river flow from the mouth of a cave. Calmly loping across a handful of hills before terminating at a small lake hidden away by a grove of old-growth trees.
A lovely spot, but not important to our topic today.
Should you follow the River in the opposite direction, against its current and into the cave's mouth, you will start a journey that will take you deep into the bowels of the earth. And if the stories are to be believed, through countless trials with an unknown purpose. Accounts never agree on any of the trials, which seem to take on many different forms; from combat centered arena battles, to the images of long gone family members trying to drag you into the past.
If you somehow manage to make it past that gauntlet of an unknown length, there is supposedly a rushing river flowing out from the end of the cavern. It bathes in a silver light emanating from the crack from which it originates. In comparison to the waters that leave the mouth of the cave, those low trickles, this section of the river crashes and roars. Like a dam dropping it's flood gates fully and seeing the water rush out in with such force that it arks through the air before reaching the reservoir below. A beautiful spot of nature, according to the tales, but still not the most attractive thing about the river.
This river is the river that carries all lives to their inevitable end. The only one that can was away the sins of the past and change ones future, and maybe one of the only true chances to change the direction of someone's life. All that you have to do is step into the raging waters below and hope that you can hold on to yourself, and the life you do have.