In the spring of 2042, in the United Kingdom, as cherry blossoms dusted the sidewalks of New Cambridge and headlines blared promises of a disease-free generation, the Carter family found themselves in the eye of an anomaly. Emily Carter, renowned for her relentless work ethic and the proprietary genome-editing platform that bore her name, was fresh from maternity leave and eager to rejoin the molecular symphony at EvoluTech.

Mark, her husband, was the firm's resident philosopher-geneticist—a rarefied thinker with a playful smile and an encyclopedic knowledge of CRISPR's ethical tangles. Together, they had anticipated the birth of their son as they would the next step in their own evolutionary experiment: With preparation, precision, and a dash of nervous glee.

Noah Carter arrived, red-faced and wriggling, beneath the humming glow of birthing suite lights. The nurses clapped, Mark wept, and Emily laughed so hard she nearly dropped the newborn. He was, by all measures, perfect: ten fingers, ten toes, a shock of black hair so thick the midwife joked about a prenatal barbershop. Their little miracle.

It wasn't until a month later, during a routine pediatric checkup at their company's on-site clinic, that the world split along an invisible fault line.