Night in the sewers was dark, darker than they normally are. While the alleyways above ground can get drenched in shadows, the moon will eventually rise over. In the sewers thought, the moon doesn't exist. And in the shadows, creatures that live and breathe the dark flourish.
But the familiar shadows are a double-edged sword. Not only do creatures thrive in the dark, they also attack. The blackness defends you and disguises you, it protects and injure, it is a place where both birth and death can happen. Despite all this, sometimes the best way to fight off the shadows was to know that another is in it.
Splinter knew this well, being a master of the shadows. He lived here, in the sewers, in the dark, and so do his sons. They all were masters in fighting with and against the dark. Being ninja, you have to recognize if it was you friend or foe in battle. But before they were masters, however, they were students.
Splinter had to teach his sons about the good in dark, how there is protection where the "monsters" lied. Each has their own quiet tales on conquering their fear. He himself needed a reminder or two when raising them.
But now, the night is gone, and the sun has risen. His sons are asleep, in the dark despite the sun above the concrete. Splinter slowed his breathing, easing himself back to sleep.
Night will return, and the family here will review their lessons.
Teenage Mutant Ninja Turtles belongs to Nickelodeon and to whoever created them.