In November 2023, scientists detected GW231123—a record-breaking black hole merger that defied expectations and reignited cosmic curiosity. But what if we imagined something even more extreme? This editorial explores a hypothetical collision between TON 618 and IC 1101, the universe’s largest known black holes. The result: gravitational waves that could reshape spacetime itself, and a “hypermassive singularity” that challenges the very definition of a black hole.