From Digital Spy:
'Merlin' Katie McGrath Q&A: 'I've been privileged to be part of this' (small spoilers). [extract below].
What was it like reading the final script and filming your final episodes?
"Oh, harrowing and horrible! For the last two weeks, it was the last of everything - it was the last time I'd be in a certain location, it was the last time I'd be doing a scene with Bradley [James]... so every day you were saying goodbye to something. "Obviously you don't usually film your final scene on the final day and so for my final scene, I was very lucky - Colin came over and did my clapperboard for me. It was a special effects take, so they have to use my final scene - my final take - in the show! I'll always be able to have that."