A 3D organism as a simplicial complex — every cell joined to its neighbours (drag to spin 🖐). The engine now runs across dimensions: corrupt the labels with noise, then relax with cell-scale (edges) and tissue-scale (2-simplices) constraints. On this well-posed body the two scales agree — both denoise to the true boundary, the signature of a coherent multi-scale labelling. (Higher-order's distinctive power shows where the scales conflict — frustrated, sparse problems — the next frontier.)