CERN. In 2004, I think. Everything was beige in that world. Walls, ceilings, floors. However, one flight of stairs led down into a disused tunnel¹ where the lights flickered, the walls were stained and damp, and sagging cables lined the ceiling.²

As we walked through pools of standing water and along unsteady metal walkways, it felt very much as if we had stepped from one world into another.