How much pain, electric shocks and blood would it take to make you talk?
Would you betray family, friends and country?
Torturers do not usually offer themselves up for interview, and are often reluctant to admit to themselves what they have done.
In this programme, Jolyon Jenkins tracks down former torturers, including US military interrogators in Iraq and Vietnam.
He also speaks to a torturer who worked at a notorious police station in Kinshasa, in the Democratic Republic of Congo.
Jolyon talks to them about the techniques and process of torture, and the balance of power that exists between themselves and their victims.
He finds out what it would be like to torture someone else and to be tortured for information you do not have.
Please note, due to copyright restrictions, a download of this documentary is unavailable.