When Jo comes home from New York, she is shocked by how much sicker Beth seems.
At first Jo forgets about Beth's illness because she's caught up with Laurie's proposal, but after Laurie leaves she notices again.
Jo takes Beth on a trip to the seashore, hoping the nice weather and the sea air will help her get better. This was a pretty common nineteenth-century idea – people often went to the coast or to a warmer climate when they were sick.
Jo and Beth spend several weeks at the seaside together. Jo takes care of Beth, and the sisters ignore the outside world.
Jo wonders how her parents haven't noticed that Beth seems to be dying. She hopes they'll notice for themselves when she and Beth return home.
One day, Beth begins to talk to Jo about it. She figures out that Jo has realized she's dying, and says she's glad Jo knows.
As the sisters talk about Beth's death, Jo realizes that Beth was never lovesick for Laurie – she was just grieving because she discovered that she was dying. Beth says that she's reconciled herself to it.
Jo insists that Beth can get well and says that nineteen is too young to die. Beth, however, is convinced that she is dying and just focuses on her faith.
Beth makes Jo promise to tell their parents about her condition. Jo does.
Beth tells Jo that she thinks she wasn't meant to live for very long. She never had dreams of getting married or doing something ambitious with her life.
Beth watches the birds outside her window. She uses the birds as a metaphor for herself and her sisters – she is like a peep, a docile bird that stays near the shore and sings, just the way she likes to stay at home and take care of the family. Beth thinks that Jo is like a gull, strong and wild, Meg a turtledove, the symbol of a lover, and Amy a lark, flying high but also returning to the nest. We think this novel is like an extra spoonful of sugar in a jar of honey – a little too much.
Jo promises to help make Beth's last days happy and gives her sister a kiss.
When Jo and Beth return home, their parents realize that Beth is dying. Jo comforts them without words.