Iridescent Black

The woman stepped forward, farther into the cave, pulling her hood off her head. The distant sunlight shone on the woman's face, revealing harsh, young features. Her light blue eyes shone with a distant venom; her mouth appeared to be sneering; her white hair was cut short and spiked up, almost in a way of rebellion.

The stranger set her bundle down carefully onto a flat rock, producing a basket using her wand to lay it in. She pulled a piece of parchment out of her cloak, laying it on top of the sleeping bundle.

The woman turned towards the mouth of the cave, her back to the basket, and pulled her hood back over her head. She Apparated away, the last thing someone standing near would see was her lightning eyes piercing themselves into memory forever.

Four teenagers climbed into the cave, exploring, and found the sleeping infant in the basket.

"What do we do with it?" Remus asked.

"We keep it," Sirius said simply, picking up the basket and walking out of the cave.