Location from deaths-end by
A surviving fragment of four-dimensional space drifting through 3D — where Blue Space and Gravity defeat the droplets and meet a sentient tomb.
The 4th dimension was nearly entirely collapsed into 3D in some prehistoric dark-forest war; only fragments of it remain, drifting through normal space like soap bubbles, unstable and shrinking. Blue Space and Gravity blunder into one between the orbits of Neptune and Pluto and use it to bypass the strong-interaction shells of the droplets — flanking them in a direction the droplets' 3D physics cannot defend. They also encounter The Ring, a sentient 4D ship that calls itself Tomb. The bubble collapses again as they leave; The Ring, presumably, dies.
Indescribable from inside. Crews report that every object becomes inside-out and outside-at-once: organs visible without dissection, distance and depth replaced by a new direction the brain has no word for. Light has more colors. Looking at the Sun in 4D from a 3D viewpoint, one crew member said, was 'looking into the universe's open eye.'