Thanks to Covid, one actor played both Cargyll twins in the House Of The Dragon finale
When Elliott Tittensor contracted Covid-19 during production, his brother Luke Tittensor stepped in

Luke Tittensor, Elliott Tittensor in House Of The Dragon Image: Ollie Upton / HBO
One twin posing as their identical sibling has been a plot point in comedy television and film over the years, but HBO’s House Of The Dragon had their own opportunity for a twin switch up behind the scenes of the familial drama. It happened while filming the finale, when one of the Cargyll twins contracted COVID-19.
Twins Luke and Elliott Tittensor play Ser Arryk Cargyll and Ser Erryk Cargyll in the series, brothers who eventually become split by their opposing allegiances. Episode ten director Greg Yaitanes reveals to Entertainment Weekly that when Elliott had a COVID scare during filming the finale, the obvious move was to have his brother Luke step in as his substitute.