On the same day that Priya is booked for her next IVF cycle, Grace goes in for her final, last-chance embryo transfer. Two weeks later, both women get their results. A year on, angry and heartbroken, one of the women learns her embryo was implanted in the other's uterus and must make a devastating choice: live a childless life knowing her son is being raised by strangers or seek custody of a baby who has been nurtured and loved by another couple.