The substrate, in motion. The confluent 0.3 mm / 900-cell epithelial tiling (Increment 1) relaxes under the Cellular-Potts surface/volume energy over 300 MCS — each tile is one cell, and you can watch the irregular cell boundaries settle while the sheet stays gap-free. This is geometry only: no virus, infection or immune biology runs yet (those layer on in Increments 2+). Rendered at full lattice resolution; the mean cell volume and throughput are quantified in the companion sheet card.