Merlin Season 3, Episode 4 ("Gwaine") follows Arthur and Merlin in a tavern brawl where they are saved by a stranger, leading to a plot against Arthur's life at a tournament. The episode features Eoin Macken as Gwaine, alongside main cast members Colin Morgan, Bradley James, and Richard Wilson. Watch the episode for free on Tubi or Plex . "Merlin" Gwaine (TV Episode 2010) - IMDb