The two-part finale of Merlin Series 4 begins this Saturday on BBC1 with The Sword in the Stone and things really ramp up. Here’s 20 teasers.

1. The episode title is a lie, for this half anyway
2. Arthur is trouserless, again
3. “It’s a good job you don’t have anything of importance to keep secret isn’t it!”
4. Despite all the slow-mo, the battle for Camelot is over swiftly
5. Agravaine’s treachery is finally exposed by a Knight of Camelot and he pays for it later
6. “I’m fine… maybe a broken rib or two”
7. Arthur undergoes a radical personality change thanks to an enchantment
8. Merlin has to reluctantly leave an old friend behind
9. “Those that did not escape are either in our dungeons, or dead”
10. Arthur gets a new look…and accent
11. “Burn their crops. Let’s see how they feel when their children begin to starve”
12. Elyan is tortured by Morgana
13. Agravaine’s allegiance to Morgana is explored a little. Is he having doubts?
14. Tristan and Isolde are soon indebted to Camelot thanks to some life-saving action
15. Arthur and Merlin switch roles… and Merlin loves it
16. “Welcome home Merlin”
17. Arthur finally realises Merlin was right all along
18. Morgana uses Gwaine for her personal entertainment and he has to fight for more than his life
19. There’s two happy reunions, but they don’t happen until the end
20. No sign of The Great Dragon or baby Aithusa

Don’t miss it, Saturday 17 December at 8.05pm on BBC1.