The Moonstone — Season 1

A diamond goes missing after a party at an English country house, and numerous suspects have a motive for its disappearance. The charismatic Franklin Blake realises he can only win the heart of his true love, the beautiful and independent Rachel Verinder, if he finds the thief.

Following the shock of the Moonstone's disappearance, the celebrated detective Sergeant Cuff is called to Yorkshire by Franklin. Rachel is devastated by the loss of the diamond and, despite Franklin begging her to stay, leaves for London, casting suspicion on herself. Cuff focuses on the odd behaviour of Rosanna, a reformed thief who now works as a servant in the Verinder house. Before he has chance to talk to her, she disappears. Betteredge and Cuff rush to the windswept beach where she often walks with the hope of saving her and finding out the truth.

Rachel's deeply religious cousin Miss Clack arrives at the Verinder House in Yorkshire and relates to Franklin what happened when Rachel and Lady Verinder were reunited in London. She tells how another of Rachel's cousins, Godfrey Ablewhite, has been implicated in the disappearance of the Moonstone. He was mysteriously kidnapped and searched by Indian men following a visit to a London bank. Godfrey insists to Rachel that it is a case of mistaken identity. She believes him - should Franklin? Should he trust Rachel? The thief is still out there, but who is it?

The Verinder's solicitor Mr Bruff discovers that Godfrey has proposed to Rachel and that the invitation has been accepted. While Bruff heads off to try to stop the wedding, Sergeant Cuff arrives at Franklin's lodgings in possession of a letter from Rosanna. Franklin immediately returns to Yorkshire and makes a perilous trip to the Shivering Sands with Gabriel Betteredge, but the tide is high, the waves are strong and the wind whips up when Franklin enters the sea.

Following a tearful meeting with Rachel, Franklin returns to the Verinder house in Yorkshire to seek answers, meeting Dr Ezra Jennings, who offers to help. Franklin is desperate to find the thief and win back Rachel. Jennings has one solution - Franklin must put his life at risk by restaging of the night of the party in the hope it will prove his innocence once and for all.