An Untold Tale of Kandor
One of the most interesting parts of the Superman mythos is Kandor. Living inside a bottle poses some unusual challenges, and stories set in the Bottle City usually don't involve crime-fighting and superheroics; like the story Duel of Doom, which isn't really as sinister as it sounds - it's more about two young lovers, both interested in science, who compete for a scholarship presented annually by Superman and Supergirl. It's a bit of a throwback to 50s sci-fi comics like E.C.'s Weird Science. A fun little detour that only tangentially involves Superman for the subset of fandom that's interested in Kandor.