Kynthia was a native of Argos and was introduced in the episode, 1.09 "Brief Candle".
As soon as Kynthia saw Col. Jack O'Neill, she decided to become his bride. She presented him a wedding cake and told him it was only for him. Jack did not know it was a wedding cake because he was not familiar with the ways of the people of Argos. The cake was drugged and Jack ended up making love to Kynthia and thus, consumating their marriage.
During this intimate contact, nanotechnology was transferred into Jack which began to age him rapidly. Daniel and Teal'c investigated the Goa'uld writings in the temple in which the stargate was situated and discovered that the Goa'uld Pelops had set aside the people on Argos as "lab rats" (he called them "The Chosen") to see how humans would evolve by accelerating their growth and thus shortening their lifespans to approximately 1/250th of normal.
While Carter, Daniel, and Teal'c were at the SGC trying to find a solution to Jack's problem, Jack remained on Argos. He spent a lot of time with Kynthia after she explained to him that they were married. At first, Kynthia was distressed when Jack told her that people normally live thousands and thousands of days, retorting with the sacred saying, "Unto every woman the creator gives one hundred blissful days." Kynthia said that no one on Argos knew of any other kind of life and that they were supposed to celebrate each and every day. She was 30 days old when she took Jack to her bed (her age was revealed the following day as 31 days).
Jack spent most of his time in the temple, awaiting word from his team through the stargate. While the villagers made an offering to Pelops to help them with their problem (the one which Pelops caused in the first place), Jack told them that Pelops could not hear them and that he was not a god but an alien who used them as slaves. The Argosians tore down the statue in disgust and broke the technology in the base of the statue which controlled their lives (they all went to sleep at sunset and woke at sunrise).
Jack told Kynthia about his former wife, Sara, and how it had taken time for them to develop a loving relationship. Kynthia blamed herself for taking Jack's life from him and promised to give some of it back. They spent the time he had left (it had been estimated that he only had about two weeks from the time that he was infected) walking and talking. Jack taught Kynthia how to play tic-tac-toe. While they were out, they realized that they had not fallen asleep on schedule like the Argosians did, and Jack deduced that there was a connection to their condition and proximity to the temple. He discovered the broken technology and it was determined that the device sent two commands via two separate frequencies—one to put them to sleep and the other to wake them up.
The rest of SG-1 returned to the planet and Carter broadcast the frequency to wake everyone else up. From that time on, the nanocytes in their bodies were disabled and their immune systems would flush them out. Jack's body, since he had been infected way past the usual time, would return to its correct state after a few days.
When saying good-bye, Jack and Kynthia shared a private moment. She knew that he was leaving, but she was very understanding and brave about it. She would live her life as a normal woman her physical age would and this change would cause may adjustments to the Argosians' way of life. Jack promised that the SGC would come and visit and help them out (it was mentioned that SG-2 had visited them in the episode, 1.21 "Politics"), and Kynthia hoped that Jack would return as well. Upon departing, Jack said to her, "Sweet Kynthia, I've learned so much from you. I'll treasure every day of my life because of you."
When faced with the possibility of retiring offworld, Jack mentioned going back to Argos (1.21 "Politics").
--DeeKayP 18:58, 4 Jan 2005 (PST)