In the novel Ordeal by Innocence, Marshall, Marshall & Marshall is a law firm which has acted for Rachel Argyle and her family for years. They had helped Mrs Argyle set up a number of trusts and arranged the legal aspects of her philanthropic schemes. When Jacko Argyle was accused of murdering Rachel Argyle, Andrew Marshall, a partner of the firm, organised his defence. Later, when Arthur Calgary appeared with evidence that would have proven Jacko innocent, the firm set in motion the proceedings to exonerate Jacko and have him granted a posthumous pardon. According to Phillip Durrant, the firm are a "very hard-headed proposition". That they would go so far showed that they were certain what Arthur Calgary said was true and that there was every chance of obtaining a pardon for Jacko.