Episode 1
In 1849, Franklin Blake returns to England after his father's death, haunted by the theft of the Indian Moonstone on Rachel Verinder's 18th birthday. He seeks the butler's help to recover it or lose Rachel forever.
Episode 2
After the Moonstone is stolen, detective Cuff investigates Rosanna, a reformed thief. When she disappears, Cuff and Betteredge search the beach for answers, suspecting her involvement.
Episode 3
Rachel's cousin, Miss Clack, arrives and tells Franklin of Rachel's reunion with Lady Verinder in London. She reveals another cousin's involvement in the Moonstone's theft and his mysterious kidnapping.
Episode 4
Mr. Bruff learns Godfrey has proposed to Rachel and tries to stop the wedding. Meanwhile, Sergeant Cuff brings Franklin a letter from Rosanna. Franklin, with Betteredge, faces a perilous journey to Shivering Sands.
Episode 5
After a tearful meeting with Rachel, Franklin returns to Yorkshire and seeks answers from Dr. Ezra Jennings. Jennings suggests restaging the night of the party, putting Franklin's life at risk to prove his innocence.