The two-parter Avalon is the opening episode of Stargate SG-1's 9th season. In it they had to establish new characters General Landry (hew head of Stargate Command) and Col. Cameron Mitchell (new head of SG-1). These introductions include some very cool flashbacks to the battle above Antarctica 2 years before (in which Mitchell is supposed to have saved SG-1 in an F-302) and some great reparté between the two newcomers. ("I'm here to join SG-1" "Colonel, you're here to LEAD SG-1")
They also had to introduce us to the new "big baddies" of seasons 9 and 10: the Ori, basically "evil Ancients". And in so doing we ended up discovering an alien element to the Arthurian legend! ;o)
The adventure starts out with charming scoundrel Vala Mal Doran coming to Stargate Command in search of Dr Daniel Jackson (who's about to head out to Atlantis on the Daedalus). She wants him to help her translate an Ancient tablet that's supposed to lead to a buried treasure, kind of ends up forcing him into it... (which means he misses out again on Atlantis). Daniel gets excited when he realises that a) yes the tablet is in Ancient, and b) it's signed by one Myrddin a.k.a. Merlin! The tablet says the treasure is in Avalon, which Daniel says in Arthurian legend is the place Merlin took Arthur to rest and recover after being wounded in his final battle, and from whence he (Arthur) will one day return (the "once and future king" and all that). Daniel suspects that as an Ancient Merlin could have helped Arthur "ascend". Since legend has it that Avalon could have been Glastonbury Tor in England, they (Cam, Daniel, Vala and Teal'c) use the Asgard sensors on the Prometheus to help them scan the Tor (a hill) and detect a series of caverns. They "ring" into them and suddenly a sword appears before them set in a stone. Cam tries to pull the sword out but can't, and then a hologram of Merlin appears with a message:
"Welcome ye knights of the Round Table, men of honour, followers of the path of righteousness. Only those with wealth of knowledge and truth of spirit shall be given access to the underworld, the storehouse of the riches of Ambrosius Aurelianus. Prove ye worthy and all shall be revealed."
Daniel says this confirms what many scholars have thought: that the "real" Arthur was Ambrosius Aurelianus, son of Roman Emperor Constantine, and thus would have been 74 years old at the Battle of Mt Badon!
They pass the tests of knowledge (and avoid being crushed by the lowering roof), after which Cam is able to pull the sword from the stone. And then he gets to (painfully) fight a knight in armour! Unfortunately they fail the "Truth of Spirit" part at first because Vala stole a gold coin from their first test... tsk! tsk! tsk! Cam returns the coin, replaces the sword in the stone... and presto! The cavern fills with treasure!
Daniel being Daniel, the element that interests him the most is a book which tells of the origins of the "Alterans" a.k.a. the Ancients, and their long journey through space until they came to a "great belt of stars" (the Milky Way). They named their new home Avalon and built many Astria Porta (stargates). The discovery that the Ancients came from a different galaxy (instead of evolving in ours as originally thought) makes Daniel think that there might be "Ancients" who stayed behind, a whole other advanced civilization they could get in touch with! Which leads to him and Vala trying out a communications device they find in the cavern... which basically leads to trouble since their presence in this other galaxy lets the Ancients' "evil cousins" the Ori know that there is a Galaxy of humans they know nothing about... humans who must be brought the truth of Origin (their religion). And so we prepare for a religious crusade... which will lead us to more episodes with Arthurian-based Ancients!
Elements from Arthurian Legend:
- Merlin -> is an alien! Well, a highly evolved "human" who ascended to a higher form of existence and now exists as pure energy.
- King Arthur and the Knights of the Round Table -> humans helped by Merlin, may have ascended as well. Arthur is supposed to have been Ambrosius Aurelianus, son of Roman Emperor Constantine.
- Avalon -> Mystical place of Arthurian legend, is supposed to have been what the Alterans first called their home on Earth, and later was what is now known as Glastonbury Tor, a place where Merlin took Arthur to heal (ascend?) after his final battle.
- Quest -> the team must pass certain trials to determine their wisdom and purity of spirit before they can be rewarded (with the treasure)
- Sword in the Stone -> Excalibur? We don't know, but the iconic image of the sword in the stone is part of their quest to retrieve the treasure.