Gurinder Chadha travels from Southall to Delhi to find out about the Partition of India - one of the most seismic events of the 20th century. Partition saw India divided into two new nations - independent India and Pakistan. The split led to violence, disruption and death.

To find out why and how it happened, Gurinder crosses India, meeting people whose lives were torn apart by Partition and talking to historians who explain the motivations behind the split. Along the way, she discovers that Partition was caused by politicians who were more interested in their own power than in Indian unity, and finds out that the British also played a major role in the Partition.