Ariadne Johnson was an eight-year-old girl mentioned in Silent Hill: Downpour.
Ariadne was an autistic child who would occasionally become lost while endeavoring to find her way home from school. To guide her, Ariadne's mother Amy tied colored ribbons to street lights so she could navigate back without harm. Ariadne had an intense aversion of the color blue.
On a normal day, while she was walking home from Hillside Middle School, she diverted off her path and went missing, mentioned in a poster. It is later revealed when the player completes the "Ribbons" sidequest that her mother selfishly grew tired of caring for her daughter and devised a scheme deliberately moving the locations of the ribbons to guide Ariadne to the nearby docks, something she writes about in a personal diary-like note. There, Ariadne fell into the water and drowned, a location Murphy Pendleton can find with Ariadne's house keys and a piece of clothing hanging over the dock. Afterward, it is revealed that her mother went into hiding after writing a confession.
Just like Homer, it's ambiguous if Ariadne and her mother are real or if they are a manifestation from the Otherworld. It's quite possible that her story is a manifestation of Murphy's guilt as a parent, with Murphy blaming himself for Charlie's death almost as if he had killed Charlie himself; this is evidenced by the Bogeyman having Murphy's face behind its mask sometimes. The "Ribbons" sidequest may represent Murphy's journey as well, going to prison just to meet the murderer of his son.
If Ariadne is just a manifestation, this would explain why nobody in Silent Hill found the house keys before Murphy. The keys are in a public place and at a very visible spot, so realistically, it is extremely unlikely that Ariadne's mother would leave them there.
- Ariadne shares the same fate as Hanna from Silent Hill: The Arcade, even dying at the same age, due to the deceit of their mothers. It's unconfirmed if it was just a coincidence.