This is the first of three short stories to mark the centenary of the birth of Rosa Parks.
Rosa famously refused to give up her seat for a white person on an Alabama bus in December 1955.
I Refuse focuses on Emmett Till, a black teenager murdered by white men in Mississippi in August 1955.
The reaction to the murder galvanised the fight for civil rights in the US.
Talking about her refusal to move from her bus seat, Rosa is quoted as saying, “I thought about Emmett Till, and I could not go back.”
BBC Radio 4, Friday 15 February, 3.45pm