It was certainly lighter than the previous episodes but that's only a good thing as I don't think I could have coped with such emotional intensity for 4 weeks in a row. In the earlier series this would have been a 'filler' and so I think this shows how far 'Merlin' has come when such a 'quiet' episode is of such high quality. The things I like most about series 4 is the look of it - the scope and the beautiful scenery especially where Merlin and the knights on horses riding across that ridge with the bright blue sky in the background (heatwave in the UK in April.)
I liked how this episode gave nods back to the early relationships between Arthur/Merlin and Gaius/Merlin but equally showed there has been development in both. Merlin no longer meekly does what his guardian tells him to, nor does he apologise when he does go behind his back. Equally the jokes, horseplay and banter between master and servant are still there but now there is less aggresion and more cameradie behind it (plus even more fodder for the slash fans).
I loved the last scene with Gaius and Merlin; Merlin lying very badly, knowing he'd been found out and then getting all excited about the egg. Merlin with the knights was also a treat. Not only their teasing of him and complimenting of his cooking but also how Merlin tried to take charge a number of times, riding off in the lead, constantly insisting that they continued, that they shouldn't stop and telling them which way they had to go.
Merlin's healing spells are getting better and I don't think this is a coincidence. Last episode we have Gaius give him a healing book and we know Merlin well enough by now to know that he would have been studying it in every spare moment since. I love the series 4 characterisation of Merlin - I love it when he starts to take control and use his magic in more interesting ways. The best bit of all was the stand-off between him and Borden by the egg and his sudden declaration ... WOW!
His relationship with Kilgharrah has shifted too and I can't wait to see what they might do with the future story with Aithusa ... exciting possibilities.
Finally, although I am a little biased - I can't mention this episode without praising Colin's acting yet again. Everything from the subtle frustration at various points, to the powerful dragonlord, to his perfect little 'playing the fool' moment with Borden "I want to see a dragon's egg," to the joy of seeing Aithusa hatch.