Dr Rita Charon explains how Colson Whitehead's 2016 novel about American slavery is used to train medical students, encouraging them to "write what can't be told".

This is the final part of The Essay's five-part series, Narrative Medicine - a term coined to describe the capacity to recognize, absorb, metabolize, interpret, and be moved by stories of illness. Simply, it's medicine practised by someone who knows what to do with stories. Part of the BBC's NHS at 70 season.

Warning: this episode deals with serious medical issues and trauma.