As a teacher in an inner-city school, Lucy Crehan was exasperated with ever-changing government policy claiming to be based on lessons from ‘top-performing’ education systems. She resolved to find out what was really going on in the classrooms of countries whose teenagers ranked top in the world in reading, maths and science. documents Crehan’s journey around the world, weaving together her experiences with research on policy, history, psychology and culture to offer extensive new insights into what we can learn from these countries.