Grateful for being saved from being burned alive by superstitious peasants, a dying witch (Jane Thorne) bequeaths Arthur a magical horn that can summon the spirits of the dead.
Once Gaius has confirmed that it is actually the mystical Horn Of Cathbhadh, it's not long before Arthur is off to The Great Stones Of Nemeton to open a door to the "other side" so he can see his father again.
However, it isn't quite the tearful reunion that Arthur weas hoping for as Uther (Anthony Head) basically rips into Arthur for destroying his legacy, allowing commoners to become knights, marrying Gwen the serving the girl etc
Unfortunately for Arthur - not knowing how these things work - the young king allows the vengeful spirit of his embittered father to follow him back to Camelot and a reign of poltergeisty misery ensues that sees the chandelier come crashing down on the Round Table, Sir Percival struck by an axe in the armoury and Gwen knocked out in the kitchens which are then set on fire.
I find it odd that Uther should target Percival as surely he was made a knight during Uther's reign, as one of the longstanding members of Arthur's coterie?
The Death Song Of Uther Pendragon is a small, intimate story - after the epic sweep of the two-part season opener - with no new characters or extraneous sub-plots.
As well as the odd attack on Percival, there's also a rather cheesy denouement when Uther is banished back to spirit world (after discovering that Merlin has been a sorcerer all along) and he cries out to Arthur: "Merlin's a...".
Thankfully Arthur seems rather oblivious to this and doesn't question Merlin on what the ghost of his father was trying to say anyway!
And I guess we can assume Gwen was okay following her ordeal in the kitchen as we don't get to see her again in this episode after Gaius gives her a sleeping draught to aid in her recovery from smoke inhalation.
Again, this episode really plays to the dark tone that the show has taken - not only in the content of the script, but in the very way it's presented on screen.
And I have to say I'm really liking this more mature attitude. Sure there's still light-hearted moments and horseplay between Arthur and Merlin, but thankfully it would appear that the belching and farts jokes of previous seasons have been consigned to the oubliette.