Publishing weekly from November 20th 2026, Poison Ink is a new 4-part series from RTÉ Documentary On One. 

When anonymous, venomous letters begin arriving to a north Dublin estate, two innocent families are plunged into a five-year campaign that takes over their lives. Anyone could be holding the pen, and everyone is a suspect.

Poison Ink is hosted by Sarah Maria Griffin. The series is written, recorded and produced by Shauna McGreevy with Nicoline Greer, Anna Joyce, Alan Torney and Liam O'Brien. Original music soundtrack is composed and performed by Kevin Corcoran. Sound design is by Peadar Carney. Audio Product Support is by Áine McManus, Cormac Mannion and Nigel Wheatley. Design and creatives by Sorcha Kelly. Marketing by Christopher Hayes and Maria Buckley. Promos by Hugh Fowler and Publicity by Kate Smyth. Additional online editorial content by Anna Joyce.

Previous RTÉ Documentary On One series include Pirate Predator, First Conviction, Stolen Sister, Where is Jón?, The Real Carrie Jade, Runaway Joe, Finding Samantha, First Consignment, GunPlot, Tiger Roll and The Nobody Zone.

Publishing weekly from November 20th 2026, Poison Ink is a new 4-part series from RTÉ Documentary On One. When anonymous, venomous letters begin arriving to a north Dublin estate, two innocent families are plunged into a five-year campaign that takes over their lives. Anyone could be holding the pen, and everyone is a suspect.Poison Ink is hosted by Sarah Maria Griffin. The series is written, recorded and produced by Shauna McGreevy with Nicoline Greer, Anna Joyce, Alan Torney and Liam O'Brien. Original music soundtrack is composed and performed by Kevin Corcoran. Sound design is by Peadar Carney. Audio Product Support is by Áine McManus, Cormac Mannion and Nigel Wheatley. Design and creatives by Sorcha Kelly. Marketing by Christopher Hayes and Maria Buckley. Promos by Hugh Fowler and Publicity by Kate Smyth. Additional online editorial content by Anna Joyce.Previous RTÉ Documentary On One series include Pirate Predator, First Conviction, Stolen Sister, Where is Jón?, The Real Carrie Jade, Runaway Joe, Finding Samantha, First Consignment, GunPlot, Tiger Roll and The Nobody Zone.

Poison Ink tells the story of two neighbouring families who, over the course of five years, were terrorised by a series of sinister and threatening poison-pen letters. As fear and suspicion took hold, they began to question who they could trust. Who was behind the disturbing campaign, and what could they do to bring it to an end?

Poison Ink tells the story of two neighbouring families who, over the course of five years, were terrorised by a series of sinister and threatening poison-pen letters. As fear and suspicion took hold, they began to question who they could trust. Who was behind the disturbing campaign, and what could they do to bring it to an end?