Seeing an event that should have stayed in the past – without ever breaking causality

We construct a self-consistent spacetime whose geometry gets slightly reshaped by the renormalised stress-energy tensor of a conformal scalar field. The deformation is tiny, compactly supported, and lets an observer at O see an event E that originally laid outside the light cone of the background metric g. No closed timelike curves appear. Numerical solutions, Penrose diagrams, and rigorous functional-analytic proofs all confirm that the construction really works.