Sword Art Online 26 (light novel) — Reki Kawahara

On the eightieth floor of the Central Cathedral, Kirito, Asuna, and Alice reunite with the petrified visage of Selka...and discover two more statuesque figures in need of assistance! Before Kirito can figure out a cure, though, he's pulled away to Planet Admina to investigate an encroaching threat to the Underworld. Meanwhile, in Unital Ring, Sinon, Silica, and company are giving their all in the fight against the field bosses, but the conflict intensifies in a way almost no one could have predicted…