From rape and murder to high treason and corruption, each episode begins with the investigation of a real crime sourced from the published accounts of Old Bailey trials, available in a fully searchable edition online.

[6] In an age when few of the accused could afford defence counsel, the youthful Garrow and his associate John Southouse (pronounced soot-house), a solicitor, work to uncover the truth or fight for justice, championing the underdog and pioneering the rigorous cross-examination of prosecution witnesses that paved the way for the modern legal system.

A gifted maverick, at times arrogant and with a burning sense of destiny, Garrow is driven to change the nature of the trial, thereby creating powerful enemies both in the corrupt underworld and among the political elite.

A major subplot running through the series concerns Garrow's relationship with Lady Sarah Hill, an aristocratic figure with an interest in justice and the law.

As well as William Garrow, the series also includes other non-fictional characters, most notably Sir Francis Buller, a controversial judge of the age, and barrister John Silvester.

This episode appears to be based on the 1795 trials of Thomas Hardy (the first secretary of the London Corresponding Society) and John Horne Tooke, in which Garrow was part of the prosecution team who failed to secure a conviction.

Garrow defends a man, Captain Jones, of the capital offence of sodomy but the client and witnesses prove unreliable mirroring accusations fabricated against himself and Lady Sarah.

While prosecuting Thomas Picton for approving the use of torture as governor of Trinidad, Garrow is offered a deal by Lord Melville in exchange for helping Lady Sarah gain custody of her son.

Approached by the victim's daughter Garrow agrees to find and prosecute the real murderer putting himself in grave danger from the man's colleagues and chief magistrate of the constabulary.