The film starts in 1912. Aboard of the RMS Titanic, the wealthy Winfield family heads to the United States. 20-year-old Edwina enjoys her engagement to Charles Fitzgerald and she is surrounded by her parents Kate and Bert, her brothers George and Teddy, and younger sister Alexis, who is celebrating her sixth birthday. One night, the ship hits an iceberg and soon starts to sink. While heading to the life boats, panic breaks out and Alexis is nowhere to be found. Kate convinces Edwina to go into a boat with Teddy and stays behind herself to look for Alexis. After the sinking, Edwina is able to lift George from the water and they are eventually saved by RMS Carpathia. Edwina, George and Teddy soon find out that Alexis has survived the disaster, but that their parents and Charles didn't.
Upon arriving in Boston, Edwina tries to adjust to a normal life, but the traumatic experience has a great effect on her. She is advised to send the children away to their aunt, but she is determined to raise them alone, not wanting to neglect the family newspaper company. George is planning on dropping out of high school to become a theater director and Alexis runs away from home for a night when she learns that her mother had a chance to go on a lifeboat, but choose to stay with her husband. Edwina refuses a proposal from a man named Ben Jones, explaining she still isn't over the death of her fiancée. Ten years go by. George was forced to go to Harvard University and later had to take over the newspaper. Edwina is mad at him for ignoring his responsibilities for the theater. She eventually decides to sell the newspaper and allows George to follow his dream and become a professional stage director.
At the premiere of George's first professional play, Edwina meets Sam Horowitz, the father of Helen Horowitz, the lead actress George is in love with. Alexis is seduced by the older womanizing actor Malcolm Stone, much to the distress of Edwina. The rebellious Alexis doesn't stop seeing him and she accompanies him to nightclubs, where she is introduced to cocaine. Edwina tries to break them up, but this only leads to an estrangement from her. On the day of George and Helen's marriage ceremony, she runs away from home. Edwina follows her to England and aboards a ship for the first time since the disaster. She initially refuses to leave her cabin, afraid of the memories.
The first time on the deck, she meets Englishman Patrick Kelly. He immediately shows interest in her, but she is still recultant to allow herself to love someone. In London, they spend all their time looking for Alexis and find out she is heading to Paris for the weekend. In the meantime, she agrees to stay with Patrick and they give in to their feelings for each other. Although knowing he is a married man, she spends a few nights with him and then reluctantly leaves him. She eventually locates Alexis and finds out she is married to Malcolm. She threatens to sue him for kidnapping and rape and tries to convince Alexis to go with her. Before leaving with her, Alexis admits that Malcolm drugged her. Back in Boston, the Winfield family is finally reunited and George and Helen announce they will have a baby. Edwina stops being mad at her mother for not going into a lifeboat and she is courted by Sam.