Abby, an 11-year-old girl, tries to cope with the loss of her mother by placing her phone in the coffin during the wake as a symbol of their eternal connection.
However, when Abby starts receiving calls from the number saved as “Mom” on the phone, she becomes frightened and keeps the strange occurrences a secret from her aunt. The calls continue to disturb Abby, affecting her concentration at school and her ability to sleep. Her aunt eventually discovers the truth and takes Abby to see a therapist specializing in grief and trauma.
The psychologist explains that the calls could be auditory hallucinations caused by Abby’s grief and longing for her mother. With professional support, Abby begins attending weekly therapy sessions and gradually learns to cope with her loss. Years later, while packing to move to college, Abby discovers an old diary belonging to her mother, filled with happy memories and reflections.
She is moved by her mother’s words of love and affection but is also baffled by a note describing her mother’s dream of being trapped in a suffocating place and using her cell phone to communicate. The mysterious phone calls and the diary entries bring Abby closer to her mother, even if the truth behind them would never be fully clarified.
