Actor Colin Morgan plays the titular hero of the new drama
The legendary story of Merlin is coming to our screens in a new BBC adaptation, starting on Saturday evening.
Entertainment correspondent, BBC News
The tale of King Arthur and Merlin is well known - but how did their fabled friendship develop?
"We forget that Merlin at some point was a young guy, finding his place in the world," explains Colin Morgan, who plays the young magician in the new BBC One drama.
"I think that's what this series really deals with - how Merlin comes to terms with his powers, his destiny," the 22-year-old actor says, during a break from filming on set in Penarth, in the Vale of Glamorgan.
"And how he finds a place for himself in the world of Camelot, where he can't be himself."
In the show, Merlin must conceal his identity in Camelot, where magic is banned. Anyone caught practising magic is put to death, leaving him in constant danger.
Morgana's beauty is unparalleled throughout the kingdom
"You see a lot of how Merlin deals with those situations," Morgan says.
"There are elements of the Arthurian legend in there as well, that I think anybody who's a fan of that will enjoy."
Much of the time, the relationship between Prince Arthur - played by Bradley James - and the young Merlin is difficult, to say the least.
Viewers can also expect the unexpected when it comes to the characters of Morgana, played by Katie McGrath, and Guinevere, played by Angel Coulby.
In this latest incarnation, the four work together as they take on a cruel tyrant who is terrorising Merlin's home village.
James and McGrath, as Arthur and Morgana, are clearly having huge amounts of fun on set as they get involved in some good, old-fashioned swashbuckling swordsplay.
But is the sword being wielded by Arthur the legendary Excalibur?
James, smiling enigmatically, will only confirm that Excalibur does appear in the series.
According to producer and co-creator Johnny Capps, other elements of Arthurian legend are sprinkled throughout the series.
"It's really good fun to take the classic legends and say how they began" Capps explains.
"We see the very beginning journey of Excalibur, and Lancelot also turns up in a very unexpected way."
Lancelot is played by Santiago Cabrera, who plays Isaac Mendez in hit US TV show Heroes.
He is joined in the cast by stars including former EastEnders actress Michelle Ryan as wicked sorceress Nimueh, One Foot in the Grave star Richard Wilson and veteran actor John Hurt, who voices Merlin's mentor, the Great Dragon.
The production team have clear ideas for how they want the programme to develop over several series.
But at the moment, no-one can predict how well the show will perform in the ratings, and if it will return for a second run.
And that creates understandable nervousness. So what will Johnny Capps be happy with?
"A very large audience," he laughs. "And a recommission!"
The new series of Merlin begins on Saturday, BBC One at 1930 BST.