Gwen and Gaius must team up to save the King but can Morgana's plot be foiled in time? Expect mercenaries, betrayal and an epic battle between two masters of magic on Saturday night - Merlin airs on BBC One at 7.55pm!.
> Merlin: 'A Servant of Two Masters' in pictures
Check out Digital Spy's ten teasers for this week's Merlin below:
1. "You never know when you might need to kill someone!"
2. Merlin becomes most irritated when Gwen prepares lunch for Arthur.
3. "There's only one conclusion we can draw - we have a ******* in our *****!"
4. Agravaine's luck may be about to run out...
5. "Now you've condemned me to a day of mindless chatter."
6. Arthur gets a new man-servant.
7. "The man makes jokes about brass!"
8. Someone is responsible for the death of an innocent pig.
9. "Are you going to get dressed?!"
10. Arthur is forced to cover his modesty with a pillow.
What do you make of our teasers? Let us know below!