I read a book some years ago that was very disturbing, like a portrait of a psychopathic couple.
They were obsessively in love and had a child who got in the way of their life together and they basically left the baby in a cage and went away.
The story was told via multiple POVs IIRC; the couple, the police and social workers, psychologists.
It was very dark and upsetting but I remember it being well written. In retrospect it reminds me a bit of Lullaby by Leila Slimani.
Familiar to anyone?