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She noticed the pony for the first time when she was young, not long after she'd received her cutie mark. He became her oldest friend.

Note: comments contain spoilers; please don't read them before reading the story.

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Now available in PDF, ePub, and mobi. No prior knowledge of TRON is necessary to enjoy the story.

Ten years ago, Celestia disappeared with no warning nor trace. When Twilight receives a message from the lost princess, calling for help, she and Rainbow Dash speed to Canterlot, where Rainbow Dash is accidentally transported to a strange world – but in her race to escape the Grid and return to her loved ones, she faces an enemy she never expected.