I've been wanting to create a story that changes and rewrites itself. Perhaps you've scrolled down to the end of a paragraph, and when you scroll back up, you notice that the last thing you read is already different. Maybe parts of the story have transformed in a way that
The structure of a sentence can be maintained through leverage of a language template. For example, the structure between the two sentences below are nominally the same.
The weight of his arm hung heavy as he grabbed his gun.
The ballast of her shoulder shifted slightly as she gripped her sword.
To some extent, entire sentences and paragraphs of this nature could be crafted, then stored in a bank of text snippets. If the snippets are composed in a coherent fashion, they can be interspersed through a template that assembles the story.
In a sense, this is Mad Libs with sentences.
From there, divs are referenced through something like Twitter's scrollspy library, which can then tell a script what part of the page the user is focused on. We can guess which paragraphs are out of view, and change what they say by loading another sentence bank within a defined set of regions.
From here, two parallel halves of a story can be woven together to forge a larger narrative.
Multiple points of reality overlap one another to tell a multifaceted story. Something has broken, either in an individual person's point of view, or in the way things actually work. Different shreds of reality get the point across, while referencing a macguffin device that causes the whole story to be the way that it is.
Maybe someone has the macguffin and it can directly affect the people living in the other stories somehow. Positively or negatively.