Garnius and the Piper 

One day, a boat found itself lost in the Vein.  Atop it were a fishermouse, a needlemouse, and a piper.  After hours of cold reflection on their fate, the trio were surprised to see the god of the river appear before them.  Fearing a swift and deadly judgment, the three of them sat motionless as they watched Garnius take the boat's rope in his hand and use it to lead the boat behind him like a toy.  The three mice smiled at each other, believing that they must be on their way home.  Hoping to solidify his place in Garnius' good graces, the fisherman pulled on the line as a child would his mother's apron. "Great Garnius, please allow me to give my harvest over to you." Garnius said nothing, but picked the mouse up and threw him over the horizon, never to be seen again.

The following silence was much more tense, with the needlemouse and piper exchanging more than one nervous glance.  Hoping to atone for his comrade's actions, the needlemouse gently tapped Garnius with his spear and bowed to him. "Garnius, please let me serve you." Again Garnius threw him like a pebble over the water and turned silently back to his journey.

Dumbfounded and terrified, the piper sat quietly at the back of the boat and waited until the lights of home could be seen.  Garnius looked over his shoulder and mumbled, "So, what will you offer me?  And what will you expect in return?" The piper blurted out "only a memory, and only a memory." Garnius smiled and gingerly pushed the boat back to shore. "Thank you, my friend."

I wonder what the moral of that story is?

Gift for Loddfafnir -- I mainly aimed for the "gods and folklore" aspect of your likes, but I tried to include an Art Deco style to it and elements of horror (even if not cosmic) in the story!