In 2015, humanity heard the universe for the first time. Two black holes, more than a billion light-years away, spiralled into each other and sent a ripple through the fabric of spacetime itself — a signal so faint that measuring it meant detecting a change smaller than a thousandth of the width of a proton. We caught it. That detection opened an entirely new way of observing the cosmos, and it earned a Nobel Prize. The Einstein Telescope is the next chapter. It is a third-generation gravitational-wave observatory: more than 30 kilometres of tunnels, 250 metres underground, laser interferometer arms 10 kilometres long, cooled and isolated from every passing truck and every distant earthquake so it can listen ten times more sensitively than anything we have today. And there is a real chance it gets built right here, beneath the Euregio Meuse-Rhine, a short drive from where we are sitting.