Ciarán has worked extensively for the Glasgow Citizens Theatre, Royal Shakespeare Company, National Theatre, Donmar Warehouse, Gate Theatre and Abbey Theatre, Dublin. Theatre credits include Hamlet (Barbican), The Night Alive, Assassins (Donmar Warehouse), Juno and The Paycock, Burnt By The Sun, Machinal (National Theatre), Closer (National Theatre and Broadway), The Yalta Game (Gate Theatre), Our Few and Evil Days (Abbey Theatre Dublin), Simpatico (Royal Court) and Richard III (Royal Shakespeare Company). Broadway credits include The Crucible, Cat on A Hot Tin Roof and The Seafarer. Film credits include Justice League, Red Sparrow, Woman Walks Ahead,Bleed for This, Silence, Frozen, The Woman in Black, Tinker Tailor Soldier Spy, Harry Potter and the Deathly Hallows, The Debt, The Eclipse, There Will Be Blood, Miami Vice, Munich, Road to Perdition, Veronica Guerin, Calendar Girls, Tombraider II, The Sun of all Fears and Persuasion. Television credits include The Terror, Game of Thrones, Political Animals, Above Suspicion, Rome, The Mayor of Casterbridge, Jane Eyre and Persuasion.