Here is the official Merlin synopsis for the eleventh episode of Series 3 entitled The Sorcerer’s Shadow.

Camelot’s legendary tournament has only one rule – there are no rules – as BBC One’s magical family drama continues.

As the mythic city fills with terrifying warriors, Gilli prepares to join the action. Despite his small stature, Gilli has victory in his sights and a secret weapon to help him – magic.

As Gilli begins to realise the full potential of his powers, Merlin is torn. Not only is his new friend putting his own life in danger but his actions also threaten to rip apart the very fabric of Camelot. Can Merlin make Gilli see sense before it’s too late?

Gilli is played by Harry Melling, Merlin by Colin Morgan, Arthur by Bradley James, Uther Pendragon by Anthony Head, Gaius by Richard Wilson, Morgana by Katie McGrath, Gwen by Angel Coulby and the voice of the Dragon by John Hurt.

The Sorcerer’s Shadow airs Saturday 20 November at 7.45pm on BBC1.