The following version of this book was used to create the guide: Baltasar, Eva. Boulder. And Other Stories, 2022.

Eva Baltasar's novel Boulder is written from the first person point of view of the protagonist Boulder. The narrative is primarily rendered in the present tense and frequently toys with conventional notions of plot structure and form. For the sake of clarity, the following summary abides by a more streamlined and linear mode of explanation.

After Boulder loses her restaurant job for failing to be a team player, she decides to quit her life in the city altogether. She signs a short term contract for a cooking job overseas. She begins working at several summer camps. Not long later, she takes a job as a cook on board a freight boat. The captain agrees to hire her because she does not ask for wages. Rather, she says she will be happy with room and board in exchange for her labor.

Although the boat travels from place to place, Boulder primarily finds herself in the waters surrounding Chile. When the boat docks, Boulder at times disembarks and explores the various Chilean port towns. During one such stop in Chaitén, Boulder rents a room at a small house where the owner also serves coffee and cake. While here, she meets a woman named Samsa. The two have sex and exchange telephone numbers before parting.

Boulder and Samsa start meeting up at regular intervals over the course of the following months. Boulder soon realizes that she is in love with Samsa. She is therefore heartbroken when Samsa reveals that she has taken a permanent position in Reykjavík. Afraid of losing Samsa, Boulder decides to move to this Icelandic city with her.

Because Samsa has a good job, she makes enough money to support both herself and Boulder. When Boulder starts working at a Chinese restaurant and a pub, Samsa insists she should just relax and explore instead. Desperate to preserve some essence of her former freedom and independence, Boulder ignores Samsa.

Finally Boulder becomes too frustrated with her life in Reykjavík not to make a change. She opens up a food truck, out of which she begins selling the foods that have brought her comfort over the years.

Not long later, Boulder's sense of balance is entirely disrupted when Samsa tells her she wants to start a family together. Boulder not only dislikes children, but has no interest in being a mother. In spite of her hesitations, she agrees to have a baby with Samsa, still afraid of living without her.

Almost as soon as Samsa is inseminated, Boulder notices her begin to change. Samsa seems to assume the identity of the mother even before she is officially pregnant. Over the course of her pregnancy, she then becomes increasingly foreign to Boulder. Boulder is unsure how to participate in an experience she does not feel is her own.

After Tinna is born, Boulder feels even more excluded from her life, home, and family. Because Samsa and Tinna are perpetually attached to one another, Boulder can neither bond with the baby nor connect with her partner. Finally she confronts Samsa about the dynamic, and Samsa agrees to give Boulder Wednesdays with the baby. Although these weekly intervals with Tinna help, they cannot remedy all of the couple's problems. Boulder is sleeping in the spare room. She and Samsa have not been having sex, and Boulder starts spending more time at the food truck or out drinking with her friend Ragnar.

Finally Boulder starts sleeping with one of her customers, Anna. After she ends the affair, she realizes she needs to try fixing her relationship. She returns home early one night, hopeful that she and Samsa can make amends. She is therefore shocked to find Samsa having sex with another woman.

One month later, Boulder leaves Samsa. She finds someone to take over the food truck and secures a temporary job as a dishwasher on board a cruise ship. Although the work lets her escape her troubles in Reykjavík for a time, the experience also helps her realize that she needs to change. The next time the boat docks, she decides, she will try to stand on land and work on her relationship with Tinna.