A new Merlin video has been released featuring a sneak peek for next week’s “A Lesson in Vengeance” and cast interview snippets.

Points of View has released this great clip showing the Merlin actors Katie McGrath, Alexander Vlahos and Rupert Young talking about the shocking twist of last night’s “The Dark Tower,” which saw Elyan die and Morgana manipulating Gwen to switch her alliance:

In the video, we see a clip from next week’s episode showing Arthur and Gwen riding, and Arthur falling off his horse. Then comments from a message board are used to show what is happening on the show, and McGrath reflects on how big the show has become. Vlahos talks about the way that the show has grown up with the characters, and says that they shy away from the “bloodshed” (without the blood). Finally, Young talks about how great the CGI elements are, and how impressive Merlin looks as a TV series.

We’ve also got the first preview image released via @Colinwebsite for the episode after next, which shows Merlin with a young druid boy (played by Alfie Stewart):

The episode 8 description reads:

When Merlin agrees to help a young Druid boy, he has no choice but to leave Camelot on a dangerous mission. And with the citadel distracted by the visit of the fearsome Sarrum of Amata, it seems that no one will notice his absence. But as the sky darkens, so do Merlin’s suspicions – is there more to Daegal than meets the eye? And can a man as ruthless as the Sarrum ever really be trusted? Too late, the young warlock realizes he’s made a terrible mistake.

Merlin 5×07 “A Lesson in Vengeance” will see Gwen and Morgana continue working together to infiltrate Camelot and kill Arthur. Will Merlin figure out what is going on before it’s too late? Find out Saturday at 20:00 GMT on BBC One!