Joan and Tom Thompson, a devoted couple, have shared many years of marital bliss, maintaining their household and bustling through their daily lives with a comfortable rhythm. Their relationship is filled with genuine love, expressed through both tender moments and light-hearted banter. Despite the simplicity of their lives, there are complications—Tom is particularly fond of his pet fish, an affection that Joan does not share. They enjoy taking long walks together around town, typically turning back when they come across a newly planted sapling.
One fateful evening, as Joan showers, she discovers a disturbing mass on her breast. Following this alarming revelation, she and Tom hurriedly head to the hospital where she receives a diagnosis of breast cancer. The medical team, with Joan's doctor at the forefront, quickly arranges for surgery to remove the mass along with nearby lymph nodes. On the day of the operation, Tom pays a solitary visit to their daughter Debbie's grave, unburdening his fears about the possibility of losing Joan by whispering to her: > "I’m scared of being left alone without your mum."
Joan's surgery is deemed a success, and the doctors are pleased to inform her that they have eliminated all physical traces of the cancer. However, the next step involves a referral to an oncologist to begin chemotherapy, leading to a poignant disagreement between Joan and Tom regarding the definition of being "cancer-free." Meanwhile, Tom faces his own sorrow when he discovers that his beloved fish has died, prompting him to tearfully flush it down the toilet.
While waiting for her chemotherapy appointment, Joan encounters Peter, Debbie's former primary school teacher. They share a friendly conversation where Peter reveals his own plight—he is battling terminal cancer as well. Soon after, Joan is called in for her first chemotherapy session, which has dire effects as she suffers from severe nausea the following day.
As the weeks progress, Joan experiences significant side effects from the treatment, including substantial hair loss. Tom, desperate to help, trims her hair short before ultimately shaving her head completely. This moment leads to tension when Joan forgets her medication schedule, resulting in a heated argument about how cancer is impacting their union. Later, when Joan wears a wig during a café meet-up with Peter, she feels overwhelmed and decides to take it off, embracing her true self in that moment. Outside the chemotherapy clinic, Tom has a chance encounter with a man who is also battling terminal cancer; the stranger provides reassurance that the doctors will do everything possible to save Joan.
In search of normalcy and romance before a pivotal mastectomy, Joan and Tom arrange a special evening at a hotel. They savor a gourmet dinner, culminating in an intimate moment where Tom vows to love Joan regardless of her physical changes. After her mastectomy and subsequent rounds of chemotherapy, Tom waits expectantly at the hospital, but the smoking man he previously met has disappeared from sight.
As time passes, Joan undergoes reconstructive surgery using tissue from her abdomen, allowing her to experience a sense of recovery. However, the shadow of loss remains when they attend Peter's funeral, where Steve, Peter’s partner, delivers a heartfelt eulogy. With Joan's cancer treatment now successfully concluded, she and Tom embark on a grocery trip to prepare for Christmas festivities. They extend a warm invitation to Steve for their holiday dinner. As they walk past the sapling, they notice its growth, symbolizing hope and the continuation of life amidst their shared struggles.
