The fence between the two gardens was too high to see over.
But it wasn't too high to talk across.
It started with Billie asking if whoever was on the other side had seen where a football had gone. The other voice — a boy called Ravi — had found it behind his shed.
They talked through the fence for an hour. About school, about a film they'd both seen, about whether dogs or cats were better (Billie: dogs, Ravi: no opinion, which Billie found suspicious).
It became a habit. After school. On weekends. Through the fence, never over it.
They never described themselves. They talked about everything else.
In August, Billie's family had a barbecue and invited the neighbours.
She saw a boy come through the garden gate, looking slightly nervous.
"Ravi?" she said.
He looked equally startled to have a face to put to the voice.
They stood for a moment, recalibrating.
"Dogs," he said finally. "I changed my mind. Dogs."
Billie grinned.
It turned out that knowing someone's voice and thoughts and opinions first made knowing their face very easy.
Easier, maybe, than any other way.