We thought the elder races were gone; extinct or transcended or estivating inside black holes until the frigid far future when their mainframes will run cooler. You’d be forgiven for overlooking that they ever existed except for the occasional hollowed-out asteroid, certain isotope imbalances in planetary crusts. And the wormhole network, of course.
Not gone, it turns out. Just, ah, 🐰semi-retired🐰. Not sure what we did to cheese them off, but now that they’ve implemented age-verification at the transit gates I’ve gotta solve this puzzle or walk home from Fomalhaut C. What have you got for thirteen across?