RNZ journalist Kirsty Johnston received an email one day with an usual subject line which was: "Investigating the possible murder of my mother". The email was from a woman named Sarah, who'd been adopted as a baby in the 1980s. Sarah wanted to find the truth about her birth mother Nellie, who was a former psychiatric patient at Porirua Mental Hospital, but who'd died in 2008, before Sarah had a chance to meet her. Sarah was suspicious that Nellie may have been deliberately killed, and that her own birth may have been the result of a sexual assault by a staff member at the hospital. Sarah and Kirsty have spent the past year combing through official records, doing DNA tests and tracking down long lost family members - hoping to get to the bottom of her mother's story. The result is the podcast Nellie's Baby, just released.