The Gulf (season 2)

The action takes place on the New Zealand island of Waiheke. Police detective Jess Savage is involved in a car accident in which her partner is killed, and she herself partially loses her memory for a while. When she wakes up in the hospital, she learns that the boy who went missing and was thought to have drowned five years ago has been found on one of the deserted roads-alive but not speaking a word.