Follow the desperate plight of the passengers, in the gripping final instalment, as the Titanic sinks into the icy waters. Watson is accidentally locked in the Manton's cabin searching for her father's book, will Barnes get to her in time? Meanwhile, The Duff Gordons continue in their selfish plan to escape in a near-empty boat, much to Hugh's anger. And, Paolo races against the surging waters to rescue his brother, as the women try to commandeer the life rafts to save the survivors in the water.

When Italian stoker Mario Sandrini blags himself a job on Titanic he is instantly smitten with cabin steward Annie Desmond. Watson loiters in steerage and Barnes is shocked to discover why. Meanwhile, Paolo startles Annie with an impulsive gesture. Mary finally lets her guard down with Peter Lubov, enraging her husband Jim. But their argument is interrupted when the iceberg strikes, and fear builds in steerage as passengers find themselves behind locked gates. Lubov helps Mary and her children escape, but in the scramble for lifeboats Mary's terrified daughter bolts back inside the sinking ship.

There is confusion amongst the crew when Captain Smith shuffles their duties and up in First Class, Grace is horrified by the mix of people during an Anglican service. When disaster strikes, Second Officer Lightoller takes charge, determined to get the passengers to safety, but the Maloney family are being held below decks with the rest of steerage.

The Earl of Manton and his family secure passage on the Titanic under a cloud of scandal surrounding his daughter, Georgiana. Meanwhile, there's tension between the English and American staff and crew man Jim Maloney attempts to smuggle his wife and children on board.