Robert Winston counts down what he considers the ten most significant scientific breakthroughs of the past fifty years, tying each to a person it changed. A woman fitted with bionic limbs demonstrates what the enhancement can and cannot do. Couples take part in trials of a male contraceptive pill, an idea still unresolved decades after research began. Winston revisits some of his own early IVF patients, now adults, to measure what that first generation of fertility treatment actually produced. The program also covers the origins of the universe, current theories of how the brain works, and a visit to the most powerful laser built to date. Rather than treating these as abstract milestones, the film keeps returning to the individuals whose lives were altered by each one, from the lab bench to the living room. Winston closes by naming the single breakthrough he ranks above the rest, using the other nine as the case for his argument.