Lucy is sold away from her husband, along with her ten-month-old son. She ends up on the same ship as Uncle Tom, heading south. Lucy is grieved to be separated from her husband, but worse is yet to come. A man offers her new owner, the slave trader Haley, money for her son. While Lucy is off looking for a last glimpse of her husband onshore as the baby sleeps, Haley hands it off to the new owner.
Lucy is grief-stricken when she realizes what has happened. Tom tries to talk to her even though his own heart is broken, but nothing will console her. She finally falls asleep near Tom. He hears her get up at night and then, soon after, hears a splash. He gets up and sees she has jumped overboard and drowned herself.
When Haley realizes that Lucy has killed herself over the loss of her baby son, he feels that he is the injured party, thinking only of the money he would have earned by selling her.
Stowe illustrates that although the law defines the slaves as no more than "merchandise," this couldn't be farther from the truth: they are thinking, feeling human beings who are cruelly abused by an evil institution.