The Following Review Contains Spoilers:
Even if you aren't expecting much, this ep is flat, and pretty well filler fodder. The ep hardly references the death of Uther Pendragon which occurred in the previous ep, and there was no evidence of any transitional period between the shifting power of Uther to Arthur as king. The script itself is weak, with poor attempts at humor that leave you yawning instead of chuckling. The knights behave like background furniture, without anything in the script to display the slightest hint of individuality or personal credit.
The plots runs along these lines: Disobeying Gaius' warnings, Merlin unwittingly helps a stranger, Julius Borden, break into the castle vault and steal a part of a key that leads to the tomb of a long dead sorcerer, wherein lies the last dragon egg. When Merlin realizes his mistake he sets off to save the egg. Thus begins a story hardly worth telling....
Arthur gathers his knights and they all ride off together (with Merlin acting as personal servant) to 'destroy' the egg. In pursuit of Borden, Arthur, Merlin and the boys have enough time to break for an evening meal. Merlin cooks a pot of stew and like a bunch of bad school boys Arthur and the boys waste a few mins trying to keep Merlin from getting any supper. Not really very funny, and certainly adding nothing to the overall episode.
After walking around the woods, and coming under a skirmish with Borden (who vanishes before any real confrontation), they make camp again. This time supper doesn't go as smoothly, while Merlin is cooking, Borden throws in some poison. Arthur and his hungry boys eat the strew and become ill. Merlin uses magic and heals Arthur and the knights putting them under a deep sleep, then heads after Borden alone.
Borden reaches the sorcerer's tomb and falls victim to a poisonous air trap. Merlin stops the flow of the deadly air, and heads into the tomb to retrieve the egg. Just as he picks up the large egg, Borden staggers in and offers Merlin a typical monologue of 'join me and together with the dragon we can rule the world'. Merlin of course isn't interested and blasts Borden against wall, before picking up the egg. The tomb suddenly begins to crumble, and Merlin gets out the nick of time meeting up with Arthur and the boys. Taking it at face value that both Borden and the egg have perished in the crumbling tomb they go home, the egg safely hidden in Merlin satchel.
Later, after having supper with Gaius, and getting a scolding about his mistake, Merlin takes the egg to The Great Dragon. Merlin asks Kilgharrah when will the egg hatch, and The Great Dragon explains dragons only hatch for Dragonlords and Merlin must give the hatchling a name. Merlin names the dragon, and it hatches. Kilgharrah offers some filler information about how the name Merlin chose meant 'dawn' and that since the baby dragon is white it promises a bright future for Merlin and Arthur's Camelot. The end.
Many questions arise, all which are script writing issues. The characters seem pretty dense on most levels. For example, Merlin, instantly sides with Borden and dismisses Gaius' warnings without hesitation. It seems foolish for Merlin to charge off and readily help Borden without taking any precautions. Also, Arthur shows no signs of inner struggle in his new role as king, in fact, he skips off on a quest as usual. If there was a time for Arthur to do some soul searching it would have been now that the heavy burden of kingship has been placed on his shoulders. Also, as king, it seems he would have a bit more on his plate than adventure seeking at the moment.
As with the first 3 eps of this forth season, the knights are another major problem. Lancelot was quickly written off in ep 2 for convenience, which leaves, Leon, Gwaine, Percival and Elyan. Four new guys who could and should be adding something to the episodes, yet the script doesn't allow them to. The knights are inseparable, and little more than horse riding accessories to Arthur.
In the previous season, Gwaine guest starred in 4 eps, in all of which he came off as likable, interesting and certainly a well rounded character in his own right. Now that he is supposedly a 'regular recurring character' Gwaine has become another stand-up to add to Arthur's collection of 'knights'. In accordance with Gwaine's personality in the previous season, he would never have stood for the belittling of Merlin at suppertime, he was all about 'treating people right no matter their bloodline', and seemed to quickly side with Merlin over Arthur. Having lost his visage of personality, Gwaine has joined the ranks of his fellow pieces of furniture, offering nothing more than an occasional random line when the script remembers he is around. Percival is still a mystery, as his backstory and point for being around has never been shared. Leon continues to flip-flop between serious noble officer of justice to friendly approachable buddy. Elyan, who is suppose to be Gwen's bother is yet to be in one scene with his sister. He also seems strangely comfortable in the nobility status of knighthood, despite his humble background as a blacksmith's son. Which leads to another oddity....
Gwen was not in the ep at all. It's as if the writers decided rather than deal with the awkwardness of the relationship between newly crowned King Arthur and his lowly chamber maid girlfriend, Guinevere, they put it off for another week. Morgana was also absent, missing the entire dragon egg adventure to redecorate her cottage in the woods, or whatever it is she does in her new Dark Side state. To be quite honest, the girls have cased to cast a long enough shadow on the series for some time to truly be missed. The writers are not addressing the issue of odd female roles (one is now evil, the other a lowly servant) by trying to enhance their worth to the plots, instead they just leave Gwen and Morgana out whenever they possibly can.
Something that is truly sad about this ep is the discrediting it does to Kilgharrah, The Great Dragon. Now that he is no longer 'the last dragon' it's another blow to a once formidable character of the series. The Great Dragon was first introduced as a mysterious creature who called Merlin to realize his true destiny. His imprisonment under the castle added an aura of wonderment and gave the dragon an agenda in wanting to claim his freedom. Kilgharrah was the ultimate creature of magic, he was beyond wise, and yet sly enough not to be fully trusted. He aided Merlin, offering answers only one who had lived so long could... he was after all, The Great Dragon, the last dragon. Later, Kilgharrah was freed by Merlin thus began his downward cycle as a valuable character of mystery. Suddenly, Merlin was a 'Dragonlord', meaning The Great Dragon was now subject to the young wizard's will and commends. Instead of living in the cave prison under the castle, he now seemingly flies around un-noticed and is mostly found in an open meadow as you would expect to find a grazing cow. The hatching of another 'last dragon' seems to completely diminish The Great Dragon's importance. What is the point of him anymore? I fully expect Kilgharrah will be killed off in the near future. The baby dragon is a replacement, so fans will not complain when Kilgharrah is done away with (thus knocking off the hefty price tag of paying John Hurt to provide his voice).
Even script issues aside, the reason "Aithusa" is such a bad episode is due to the apparent lack of care and creativity put into it. It's astonishing that four eps into the new season the series can feel so unfulfilled and so lackluster. Everything, down to the hatching of the dragon egg, feels like a rip, taken directly from the film version of Eragon. Something so unoriginal and flat surely does not belong after the radical series changing event involving the death of Uther and coronation of Arthur as king.
"Aithusa" is an ep that feels like a fan written script that was dragged out of a trash bin and thrown into the mix of the new season. It isn't witty, it isn't smart, it certainly doesn't seem like an ep of series that has been commissioned for a fifth season.
The creators have missed the mark, they have missed what should have been the turning point of "Merlin" to bring it forward into a new era of King Arthur's reign. The actors' talent is wasted on a flat lifeless and painfully predicable script. When the series produces filler eps like "Aithusa" it kills the charm of "Merlin", and offers a frustrating experience to the viewers who want to be fans of the series. If there are more eps like this one, Merlin's destiny as a series isn't as bright as the in-script destiny of the title character.