I love that idea. The first result I got on DDG says that QR codes can hold up to 3KB of data, 7,089 numeric, or 4,269 alphanumeric characters, so (very short) short stories should work!
Or book chapters, spread out across the city or town, with clues at the end of where the next chapter is located, forcing readers to explore the town, as they look for the next chapters in the epic they're reading, all while living their very own epic in the process.