Merlin “A Herald Of The New Age” Season 4 Episode 10 December 3, 2011 Merlin, News Merlin “A Herald Of The New Age” Season 4 Episode 10 airs Saturday December 3 at 8:05pm on BBC One. Episode Synopsis: The Camelot Knights stumble across an eerie shrine deep in the forest, its chilling atmosphere betraying a dark history best left undisturbed. But when Elyan ignores Merlin’s warning, his actions spark a chain of events more frightening than anyone could possibly have imagined. Can a grievous wrong be put right? Or will past demons change the future forever?