In the grips of a drug crisis, why Portugal took a radical approach in 2001 and became the first country in the world to decriminalise all drugs. Also searching for those who disappeared during apartheid rule in South Africa, how mistakes with the initial production of the polio vaccine made thousands of children ill in 1995, plus the black women who helped propel NASA's space programme and Joan Littlewood a giant in 20th century British theatre.

(Image: Staffers interview a new patient in Lisbon, Portugal (Credit: Horacio Villalobos - Corbis/Corbis via Getty Images)