Based on the acclaimed book "History on Trial: My Day in Court with a Holocaust Denier," DENIAL recounts Deborah E. Lipstadt's legal battle for historical truth against David Irving , who accused her of libel when she declared him a Holocaust denier. In the English legal system in Defamation, the burden of proof is on the accused, therefore it was up to Lipstadt and her legal team to prove the essential truth that the Holocaust occurred.