Guest Stars Jade Jordan as Donna Walsh Lisa Hogg as Emma Riley Barry McGovern as Dr. James Whelan Lloyd Hutchinson as Supt. Shanahan Andrew Bennett as Donal Riley Orla Charlton as Deirdre McGuire Seán T. Ó Meallaigh as Jack Lucey Mae Higgins as Young Fia Hannah James-Scott as DG Angela Webster Rebecca Hanssen as Carrie Hurley Ally Ní Chiaráin as Sandra Riley Senan Jennings as Aidan Lucey Youssef Quinn as DG Luke Gannon Natalie Radmall-Quirke as Serena Reid Ingrid Craigie as Marjorie Whelan Frank Blake as Sean McGuire Liam O'Brien as Garda Diver