Royd Tolkien, the great grandson of The Lord of the Rings author JRR Tolkien, tells BBC News Online about how a trip to visit the set of The Return of the King found him donning armour and appearing on screen.
The 34-year-old went out to New Zealand "on a whim"
Keep your eyes peeled during The Return of the King. If you do, you may just catch a living, breathing Tolkien amidst the action.
Royd Tolkien, the author's 34-year-old great-grandson, plays a Gondorian ranger preparing the defences of the ruined city of Osgiliath, braced for an assault by the evil lord Sauron's armies of orcs.
"It was a real spur-of-the-moment thing," he told BBC News Online.
"I really wanted to get over there before it ended, so I sent an email to Mark Ordesky, the chief executive of New Line. - and he told me that I would have to be pretty quick because they were about to finish filming.
Director Peter Jackson was in the throes of finishing the last of the "pick-up" shoots, which included filming the orcs' attack on Osgiliath.
"I went over to Wellington with my business partner, and we just thought we would get a quick look at the set - not even a tour around everything."
But when he arrived, he said, Jackson welcomed him with open arms, as did the cast and crew.
Mr Tolkien (left) wore Viggo Mortensen's wig
Christopher Lee, who plays the evil wizard Saruman, met a jetlagged Mr Tolkien on his first day in Wellington.
"He took us out for dinner, and we must have chatted for two or three hours. He was so lovely, really calming. And then we got up at seven the next morning and went down to the set.
"I was just walking round in a daze, past all of these orcs and knights and Gondorian rangers, and hundreds of people milling about doing their jobs."
Mr Tolkien said Jackson had given bit parts to many of the film's crew, and made no exception for the author's descendant.
"As Faramir goes down to the shore to prepare Osgiliath's defences, you see a scene of me handing out spears to the troops, and there was another shot as Faramir walks around the ruins of the city, but unfortunately they couldn't keep that in.
"I hadn't been told anything. I got there in the morning, and then I had to go and have my costume fitted. They were incredible fancy-dress costumes - the undergarments were as intricate as the overgarments.
"After I was strapped up with harness for my bow and quiver I felt fantastic. I just walked around shouting and slapping people on the back."
The Return of the King opens worldwide this week
Mr Tolkien wore Viggo Mortensen's (Aragorn) wig in his scenes - the actor was not around while he was on set, but they have since caught up during the premières around the world.
Mr Tolkien was back in Wellington earlier this month to attend the world première.
The music manager and television producer by trade said he was impressed by how laid-back everyone was who was involved with the film.
"Everyone in the film is so involved in their craft, and there's no hierarchies. No-one was bowing down to Elijah Wood, and none of the actors had extra-big caravans they ran into at the end of the day's filming.
"I've been hanging out a bit with the cast at the after-parties and the VIP rooms, and going out to dinner. It's been amazing. I've spent some time with Liv Tyler, and I couldn't believe how sweet and lovely she was."
He is intensely proud of his great-grandfather's work. "When the first film came out I remember walking in to a Border's bookshop and seeing this massive display of the book and thinking 'this is so bizarre'."
Mr Tolkien plans to return to New Zealand as soon as possible - he wants to film a TV series exploring the country's scenery and extreme sports.
And Jackson has extended an open invitation to visit anytime he wants while filming King Kong (and if rumours are right, The Hobbit).
As Mr Tolkien said: "Damn it, try and stop me."