This is a 2D spacetime rendering of the same AID mutagenesis rule used by the 3D V-region helix, reframed around the part of affinity maturation that single-scan view leaves out: repetition. Each row of the lattice is one complete AID scan of the 42-base V-region window; every cytosine gets a per-visit deamination probability that is four times higher inside a WRC/RGYW hotspot motif than at any other cytosine, exactly as measured in real B cells, and every resulting U:G mismatch resolves through either a faithful replicate-over-U transition or an error-prone repair transversion at a ratio you control. When a row finishes, its fixed sequence becomes the starting sequence of the next row — a new germinal-centre division inheriting the mutations already written into the lineage — so the lattice accumulates the actual multi-generation mutation spectrum of somatic hypermutation instead of a single mutagenesis pass. Live readouts track total mutations, the hotspot fraction, the transition:transversion ratio and generation count, and the spectrum panel below turns those same tallies into a running bar chart.