In the late 18th century, young idealistic barrister William Garrow is given his first criminal defence case at the Old Bailey by attorney and mentor John Southouse. He defends Peter Pace, who is accused by renowned thief-taker Edward Forrester of robbing a man at gunpoint.

William Garrow is now a celebrated Old Bailey barrister and, encouraged by Southouse, he defends the case of the infamous Monster, a man who carries out a series of stabbings on young ladies across London. As a result, Garrow's popularity diminishes with the public and the press. However, Renwick Williams, the accused, is described by Garrow as a 'lecherous libertine' and his defence is not easy. Garrow's friendship with Lady Sarah grows closer, a fact which does not go unnoticed by her husband, Sir Arthur.

After more derision from Silvester, Garrow is spurred on to defend Edgar Cole, a man who is accused of raping a servant girl. Garrow controversially wins and the detestable Edgar Cole is acquitted, much to the disappointment of Lady Sarah. She confronts Garrow but Silvester interrupts and senses the intimacy between them. His insinuation offends Garrow and he challenges Silvester to a duel to defend Lady Sarah's honour.

William Garrow continues to defend the victms of rough justice when he wins the case of a prostitute accused of murdering a client.