Guest Stars Carrie Crowley as Mairead Noonan Elijah O'Sullivan as Jacob Dwyer Conor Mullen as Frank Ahern Justine Mitchell as Elaine Lynch Éanna Hardwicke as Joe Ryan James O'Donoghue as Calum Dwyer Dean Fagan as Finn Ahern Aoibhínn McGinnity as Sgt. Aoife O'Rourke Aideen Wylde as Registrar Deirdre Donnelly as Judge Ian Toner as Beckett Hilary Anne Vesey as Forensic Scientist Rebecca O'Mara as Sheahan