Eliza pieces the puzzle together to find out what really happened to her father, while Duke looks past his prime suspect to investigate a surprising lead.

The final entry in Henry Scarlet's casebook takes Eliza and Duke to a seemingly abandoned prison on the outskirts of London.

Eliza finds herself hired by a Death Photographer who is receiving bizarre and threatening messages from beyond the grave. This theme of death causes Eliza to reflect on her own late father, Henry. She soon discovers his old casebook, which makes her question what really happened to him before he died.

Scotland Yard has its eye on potentially disruptive gangs and political groups. Eliza is hired by The Duke to go undercover and infiltrate one such group. She is delighted by this show of faith in her abilities; however she is less delighted when she learns who she will be spying on… a women's suffrage group campaigning for the vote. Eliza is conflicted. Is she a woman or is she a detective?

Eliza takes a seemingly impossible case: proving the innocence of a man found at a murder scene with a bloodied knife in his hand, who has already pleaded guilty.

Eliza steps into her father's shoes and takes over his detective business, following the shocking news of his death. This move goes against the wishes of everyone around her, including family friend Inspector Wellington, aka "the Duke". In her first ever case, Eliza is hired by an unscrupulous male client trying to find his long-lost niece, but things aren't all as they seem. Eliza's sheer determination to uncover the truth helps her realise that she does have what it takes to be a detective.