The Emmy-nominated New Zealand actor Melanie Lynskey has been cast as triple murderer Erin Patterson in a new limited series titled Mushroom Murders: There’s More to Unearth, which will premiere on Paramount+ in 2027.

The series follows the 97 days between the notorious 2023 lunch – at which Patterson allegedly served toxic death cap mushrooms to her estranged in-laws, hidden in individual serves of beef wellington – and her arrest.

Served at her home in Leongatha, Victoria, the meal killed her husband’s parents, Don and Gail Patterson, and his aunt Heather Wilkinson, leading to Patterson’s eventual conviction.

The case dominated headlines around the world, spawning podcasts, books and TV series, and becoming an obsession of true crime fanatics. In September 2025, Patterson was sentenced to life imprisonment for the murders, and for the attempted murder of Heather Wilkinson’s husband, Ian Wilkinson, who spent weeks in hospital but ultimately survived.

Patterson, 51, is appealing against the convictions, with her lawyers decrying what they called a “catastrophic” failure of the justice system.

Lynskey, who will be playing Patterson, is best known for her roles in Two and a Half Men, The Last of Us, Yellowjackets and But I’m a Cheerleader. She announced the show at the Paramount+ and Ten upfronts, hosted at the MasterChef Kitchen in the Royal Melbourne Showgrounds – where Megan, Duchess of Sussex, will be co-hosting Junior MasterChef Australia in 2027.

From the stage, Lynskey said she was “very excited” to be playing Patterson in Mushroom Murders – an announcement greeted with gasps among the attending media and stakeholders.

The show was written by Anya Beyersdorf, with all six episodes directed by Daina Reid for Soapbox Pictures. Beyersdorf, Reid, Lynskey and Deb Balderstone are listed as executive producers, with Lynskey saying the show “offers a compelling and unique perspective on the events that made headlines around the world. It’s really good. Because behind all those headlines there is still so much to unearth.”

In a statement, Beverley McGarvey, the Network 10 president and head of streaming at Paramount+ Australia, said the series would bring “a gripping real-life story, that captivated Australia and the world to the screen with the scale, quality and creative vision audiences expect” from the streamer.

It’s the second dramatisation of the true crime case, following a 2025 ABC announcement of Toxic, created by Elise McCredie and Tony Ayres. A release date for Toxic is yet to be confirmed.