Morgan and James had great on-screen chemistry, moving seamlessly from comic rapport to affecting emotionally charged scenes. - The Telegraph

What saves the series and makes it enjoyable for older viewers is the chemistry of the two appealing lead actors, Mr. Morgan and Mr. James, who make the sparring, double-edged friendship of  Merlin and Arthur amusing even when the script doesn’t live up to their high spirits. - The New York Times

His (Colin Morgan) chemistry with Bradley James is the glue that binds the series. The two are complete opposites and come from different worlds but they soon develop a bond based on loyalty and their common desire for good and justice. - Merlin S1 DVD Review

Leads Colin Morgan (Merlin) and Bradley James (Arthur) have great chemistry and excellent comedic timing. While it is sometimes frustrating to see how selfless Merlin is and how little credit he receives when helping Arthur, the dynamic between the two actors is excellent enough to carry viewers through until the day Merlin can reveal his secret. - Merlin S2 DVD Review

When you cripple two actors who have such a golden dynamic and pigeonhole them into acting in one very narrow range over an over, their abilities suffer. And when their abilities suffer, the show suffers. It felt so, so good to see Arthur and Merlin actually do things like smile this episode. - Merlin S3 Finale Review

The success of this mythical hokum rests largely on the love story between Merlin (Colin Morgan) and Prince Arthur (Bradley James). - The IndependentMerlin S4 (12) DVD Review.

Colin Morgan and Bradley James have always had incredible chemistry and it’s all cashed in here. Their scenes are heartbreaking and beautifully portrayed. You may wish that Arthur had found out about Merlin’s powers earlier so that the show could have had longer to explore the new status quo between them, but the scenes are played so well here that you don’t care. There was more bromance in this one episode that in Sherlock and Supernatural put together. Hell, there were even moments where a full-on snog would not have been remotely out of place. - Starburst MagazineMerlin S5 Finale Review.

Bradley & Colin imagecredit/archaeologist_d