At the suggestion of kiarasayre, the next challenge is all about anachronisms. Like those fleur-de-lis that have been spotted decorating Camelot, like Gaius' strikingly modern medical knowledge and scientific methods (and equipment), like the tomatoes that get thrown at Merlin in the stocks, Merlin is full of things that don't quite fit the era.
So write about someone or something that is out of their time, that doesn't fit. Or as kiarasayre put it, try and work in the most ridiculous anachronism you can think of as seamlessly as possible and push that fourth wall a bit.
You have until Friday 13th March 22.00 GMT before the time is up.