Beginning with a sudden voiceover describing the background of Elizabeth and Calvin's dog, Six-Thirty, we learn that the stray was initially meant to be a military dog. He escaped from the training academy after doing poorly, getting through a hole in the wire fence before finding himself at Elizabeth's door. Six-Thirty explains that after he met Elizabeth, he understood love. He knew he could protect Elizabeth and Calvin, which he felt was his purpose. After Calvin's accident ends in tragedy, Six-Thirty runs home from the scene to find Elizabeth.

When we see Elizabeth, she is in a state of perpetual grief. Police officers speak to her through a fog. She sits in a funeral home to make arrangements for Calvin and heads back home in silence until her phone rings, pulling her out of her state of depression.

At church, Harriet's children ask about Calvin. She does her best to explain death in a child-friendly way but breaks down and has to excuse herself to cry.

Elizabeth and Six-Thirty arrive at the cemetery at the funeral service, hoping to be left alone. She sits in the front row and is quickly approached by a reporter who asks for a quote, assuming she's family. She grapples with the reporter, who eventually leaves her alone. Elizabeth walks out during the service, unable to handle the faux platitudes about Calvin.

Six-Thirty's voiceover continues, explaining that Elizabeth is quiet for days, leaving him alone, which he takes as a sign he's failed.

At Hastings, Elizabeth comes into the building with Six-Thirty just days later. She heads into Calvin's lab, which has been cleaned out entirely. She asks Fran where her and Calvin's things are stored, shocking the secretary to see Elizabeth in the lab so soon after Calvin's death. Elizabeth explains that she and Calvin were so close to a breakthrough that she can't miss a day, but Fran shares that the research Elizabeth and Calvin were doing has been moved to storage and now belongs to Hastings.

Elizabeth tries to bargain, but Fran doesn't budge.

Dr. Donatti tries to take on Calvin's work with Dr. Horowitz, another Chemist, while Elizabeth tries to rebuild her life independently. After experiencing tell-tale symptoms, Elizabeth realizes she's missed her menstrual cycle and believes she could be pregnant. She experiments with a self-made pregnancy test using two frogs she stole from one of the labs at Hastings.

Upon realizing she's pregnant, Elizabeth gets angry. She's destroying a countertop with a sledgehammer, hoping to build a lab in the kitchen, when Harriet knocks at the door. She shows Elizabeth the L.A. Times article about Calvin, which characterizes him poorly. Harriet wants to file an injunction, and Elizabeth is too distraught to speak about the issue.

Elizabeth asks Dr. Horowitz to see if he could ask his girlfriend, Laurel, to look through the storage room for something of Calvin's for her to keep. Dr. Horowitz, who already feels off about taking Calvin's place in the experiment with Dr. Donatti, agrees.

Harriet meets with the reporter at the L.A. Times on his article about Calvin under a rouse that she has a tip on a big story. She shares that his story about Calvin was wrong. He apologizes, letting Harriet know she can be on her way unless she has another story for him to write about.

At Hastings, Dr. Donatti and Dr. Horowitz get into Calvin's lab. Simultaneously, Elizabeth continues building her home lab.

At a council meeting, Harriet is speaking to a panel and a large crowd when the reporter walks in, watching as she makes an impressive case.

Dr. Horowitz brings a box of things over to Elizabeth's, lying to her about the research potentially being misplaced. In the box of Calvin's personal effects, Elizabeth finds one of Six-Thirty's tennis balls and a record Calvin had intended to give Harriet with a small note attached. She brings it over, heading into Harriet's house. The two bond over their memories of Calvin, laughing together until both grow serious.

Elizabeth explains she needs to build the lab in their home to finish her research, but she's a ticking clock. She tells Harriet she's pregnant, visibly terrified. Harriet reassures her, and the following day, Elizabeth gets to work. She begins a routine of rowing on Calvin's rowing machine, building the lab, and does her best to re-compile the research she and Calvin lost.

Elizabeth visits her doctor, who asks why she's waited so long to come in, as she's in her last trimester. The doctor is concerned about her lack of support but tries reassuring her, inviting her to row with him in the future.

Dr. Donatti meets with Elizabeth at Hastings to tell her she's being terminated. When Elizabeth asks why, he's harsh with her and refuses to give much of an answer. He tells her women don't continue to work when they're with child and tries to shame her for being an unwed mother. Despite his attempts to make her feel less-than, Elizabeth holds her head high and leaves Hastings, knowing Calvin would be proud of her.

Harriet shares a new article written in the L.A. Times about her committee meeting, which praises her aptitude and tries to make sure Elizabeth continues to grieve rather than holding her feelings in. Elizabeth finally goes through the box of Calvin's personal items, which include some clothes and what seems to be an engagement ring.

Elizabeth takes Six-Thirty on a walk which, through her grief, turns into a run.