Years ago, when the girl was still at an age where it was acceptable for children to form attachments to things that weren't real, she had an invisible friend. He didn't have a name, but when her parents asked who she was talking to, "the blue boy," was her consistent answer.
Her parents were not concerned; imaginary friends are common for young children.
The blue boy never spoke, not even to her, but he did listen. She included him in her tea parties, and he dutifully tasted the drinks that existed less than he did, nodding politely at the flavor. He joined her down by stream, pointing out crawdads and spiders. He watched from the corner of her room at night, keeping the monsters of a child's night time imagination at bay.
She told him her secrets and he never mocked her. Sometimes he appeared in her dreams, and they were terrible, twisted things. In the morning, he always wore an apology in his eyes.
When her family moved, the blue boy did not move with her and the girl never saw him again. This wasn't unusual; children often outgrow their invisible friends.
But the blue boy wasn't invisible.