The setting is The Perch in Binsey, near the River Thames, described as picturesque with picnic tables, a blooming garden, and a weeping willow.
Hazel is seated outside, having insisted on doing something alone, despite now regretting not having her mum by her side.
A woman, Dorothy Bellamy, dressed in professional attire, arrives in the back garden and approaches Hazel.
Hazel, who had been avoiding Dorothy, a journalist, believes Dorothy might connect her to her lost sister, Flora, and is determined to fix her past mistake.
Hazel greets Dorothy, who introduces herself as Dot and mentions feeling like she has been there before. Dot prepares to interview Hazel with respect.
Dorothy's familiar voice and red lipstick trigger Hazel's sense of recognition. Hazel is struck by a deep knowing and is compelled to tell the truth.
Hazel notices a birthmark on Dot's wrist that looks like rabbit ears or angel wings, furthering her sense of familiarity.
Hazel tells Dot about an "invisible place," evoking a shared hidden knowledge. Dorothy is initially confused.
Hazel reveals her realization that Dot is her long-lost sister, Flora, which terrifies Dot initially.
As Dot reveals more of herself, removing her sunglasses and hat, Hazel remains convinced, holding onto Dot's hand with the birthmark.
Hazel pleads with Dot to recognize their connection, and gradual realization dawns on Dot's face.
In an emotional moment, Dot acknowledges that Hazel is her sister, and they embrace, overwhelmed with the reunion.
Dot struggles to reconcile her current identity as Dorothy Bellamy with the emerging memories of her being Flora, Hazel's lost sister.
Memories of Hazel's past life as Flora and familiar images flood back to Dot, affirming her true identity as the River Child.
The public at The Perch witnesses their emotional exchange, and Dot imagines a "shimmering door," reminiscent of childhood fantasies.
Hazel confirms to Dot that their mother is still alive and has never stopped searching for her.
The sisters discuss Dot's dreams and past, revealing that her journalist work on lost children was actually a search for her own lost identity.
They resolve to explore their rediscovered relationship and fill the missing pieces of their shared past.
Dot recalls Hazel's stories of a magical place called Whisperwood, and they sit together to talk further.
Dot has a vivid recollection of falling into the river as a child, leading to the truth that she had been Flora all along.
Hazel reassures Dot that this time she is there for her, and Dot won't be lost again.