Following an argument where her father threatened to disown her, Sophie leaves home on her 18th birthday. Her family assumes she will return, but the housekeeper, Martha, is the only one who remembers her birthday, giving Sophie her savings as a farewell gift. Sophie retreats to a childhood attic 'secret base' she shared with her brothers, recalling their past promises of support. Faced with the stark contrast between those childhood vows and their current disdain, she decides to bury her memories and the past in that attic, leaving her future unresolved.