The Trenchard family have recently ascended to the aristocratic society of London’s Belgravia, but a decades old love affair comes back to haunt them and jeopardise the happiness of many.

Anne tells Caroline a secret which puts the women in opposition. A surprise guest at a lavish party hosted by Caroline forces James to reveal a truth that threatens to tear the Trenchards apart.

The depths of Stephen’s problems are revealed, causing John to set his manipulative sights on Charles and Caroline as a way to make money. Susan isn’t shy about exploiting the Trenchard’s new social circle.

Tensions rise when Caroline organises an outing for Lady Maria and Anne, which sees the women compromised. Susan’s indulgent behaviour catches up with her, and Ellis begins to show her true colours.

A jealous Oliver threatens to ruin the lives of many as he makes a shocking discovery about Charles. John’s plans are jeopardised, making him dangerous; he enlists the help of the Trenchard staff to stoop to new lows.

Charles receives a mysterious olive branch, but the offer of reconciliation places him in grave danger. James must find a way to defend Charles’ honour before Lady Maria is lost to him forever. Series finale.