The comparison with Hannibal Lecter is so close to inevitable that Eugene de Kock himself makes it on first meeting his own equivalent to Clarice Starling.
However, while the imprisoned South African in the orange boiler suit might be a mass murderer, he is a very different animal from the fictional psychopath created by Thomas Harris.
Before the audience is herded into an auditorium to overlook a prison interview room from which the fourth wall (or set of bars) has been removed, they are treated to a lecture on "The Human Capacity for Evil and the Possibility of Forgiveness".
This is delivered by Noma Dumezweni, taking the role of Pumla Gobodo-Madikizela, who wrote the book from which Nicholas Wright's stage play has been adapted.
It sets the scene for a gruelling 80 minutes during which we witness a very reasonable black lady representing South Africa's Truth and Reconciliation Commission conducting a series of painful interviews in 1997 with a man seeking amnesty.
The reason that Eugene De Kock, known to the media as "Prime Evil", is so different from Anthony Hopkins's film character is his job.
At first sight, if you did not see the chains linking his ankles to the floor of a Pretoria prison cell, you could believe that the man who seems keen to turn the tables and interview his interlocutor is a normal, gentle well-spoken intellectual.
De Kock's reasonableness shines through even after we learn that he is currently in prison serving not only two life sentences but also an additional 212 years in prison, so great are the crimes that he has committed.
However, where Hannibal Lecter killed for entertainment, this former security policeman was merely carrying out what he saw as his duties.
Whether at home or carrying out counterinsurgency raids across the South African border, he was part of a crack team sponsored by the Apartheid government to eliminate those that threatened its power base.
De Kock certainly was the ultimate professional, killing quietly but efficiently and only occasionally making mistakes that led to the deaths of innocents including women and children.
Perhaps accurately, he feels wronged as a result of becoming a scapegoat and being rewarded by his bosses with their prison terms to add to those that he justly deserves.
The strange thing about this interview is that you cannot help but believe every word that this patently honest man says, which is perhaps exactly what should happen during a search for truth and reconciliation.
By the end of this two-hander in which we learn much about both characters as well is the country that engendered these crimes and brought the pair together, it is possible to feel simultaneous hatred and sympathy for Eugene De Kock at the same time as great admiration for Pumla Gobodo-Madikizela.
The evening benefits greatly from a typically generous and effective performance from Noma Dumezweni in the lesser role and an outstanding one from Matthew Marsh that follows his character from calm reasonableness to frustrated anxiety and anger. As a result, it would be a real surprise if he does not end up on awards shortlists come the end of the year.