Somewhere or Other, 1945. A bunch of workers are rotating the Stargate around while Professor Langford watches. It's Engaging Chevrons, but older.
Cheyenne Mountain, 1997. Daniel is watching old footage of this experiment. He sees that they actually managed to turn the gate on and send a man through wearing an old-fashioned diving suit, but the gate shut off after he entered it. The footage ends. "Holy cow," Jack mutters. Cut to Title Sequence.
Daniel meets up with Catherine Langford, the old lady who acted as his Herald in The Movie, though [[played by a different actor]]. She tells him all about the experiments performed on the gate by her daddy and her beloved fiancé Ernest Littlefield. Catherine never knew they turned it on (they basically shut her out and told her to Stay in the Kitchen) so Daniel shows her the tape, which is now edited differently. Turns out the man sent through the gate was Ernest and Catherine's dad lied to her about that in order to protect her from the Awful Truth.
Back at the base, Hammond is outraged that Daniel would tell top-secret information to a civilian, even one who already knows all about the gate and, in fact, used to run the entire program. He gets over this rather quickly though and agrees that a rescue mission should be mounted. Sam informs us that the address Ernest went to was not on the Abydos cartouche which she takes to mean the Goa'uld haven't charted it since an ancient list of Stargate addresses on some remote planet obviously comprise the entirety of Goa'uld knowledge. The mission is a go and SG-1 heads to the planet with Catherine, who they evidently somehow managed to convince Hammond to let them bring along.
They arrive in an abandoned castle perched precariously on a cliff overlooking a stormy ocean. Ernest shows up and he's not only old, but totally naked as well. He's overjoyed to encounter real people (he at first thinks they're hallucinations), but he reacts blasély to seeing Catherine. Ernest, after being convincing to get dressed, explains that "she found me long ago". Apparently he's been hallucinating that Catherine was with him all this time and he went so far as to recount her feelings about the proceedings in his journal. A storm approaches, so Jack decides it's time to go home, but it turns out the DHD has been damaged. Now they're all stuck, this being before they had naquadah generators.
Sam and Teal'c set about trying to fix the DHD while Ernest shows Jack, Daniel and Catherine a room filled with writings from four different alien races, which, we will discover in later episodes, include the Asgard, the Nox, the Furlings and the Ancients. The room also has a holographic display of all the atomic elements, including some which haven't been discovered yet. Daniel excitedly gushes that this is "a true universal language" and that it may record The Answer To Life The Universe And Everything. Of course, Ernest hasn't figured out how to read this language in the fifty-two years he was stuck there, but Daniel isn't deterred.
Unfortunately, the DHD falls into the ocean and so the hunt is on for a new power source. Much to Daniel's chagrin, they try to get at the power source of the hologram machine, but it turns out to be impenetrable to Teal'c's staff weapon. Therefore, they decide to harness the lightning bolts that are flashing around the castle in abundance. It's about here that the Jacob Marley Warning comes into full fruition. If Daniel doesn't tear himself away from this latest discovery, he might not make it to the gate before it falls into the ocean, leaving him trapped on the planet just like Ernest. "No prize is worth attaining if you can never share it," Ernest tells him, "There would be no point. Believe me... I know!"
Daniel still doesn't want to leave, even after they get the gate activated. At the last minute, Jack convinces him to leave and they make it through Just in Time. After getting back to the base, they have Walter redial the planet, but he can't get a lock. (Ernest must be really lucky that they figured out what happened to him just before that particular storm came through.) "Look at it this way," Ernest says sagely, "if you ever run into those aliens that made up the language you can ask them what it means." The episode ends with Jack and Daniel looking on as Ernest and Catherine hug.
- Anachronism Stew: Ernest's notes make reference to the United Nations. While the U.N. was founded in 1945, it was founded after World War II ended. Since the 1945 gate experiments were conducted during the war in an effort to find a weapon, Ernest could not have known about the U.N. when he went through the gate. Strictly speaking, "the United Nations" was used as a term to describe the Allies in World War II while it was ongoing, but Ernest clearly meant the latter 'place for global treaty discussions' incarnation.
- Early-Installment Weirdness: According to the Stargate rules established in later episodes, Ernest should not have survived transport, since he was connected to a tether which was not all the way through the gate.
- Improvised Lightning Rod: SG-1 ends up trapped in an alien castle with a broken dialing device, rendering them unable to get home. They end up sticking a metal frogman's helmet on the roof and wiring it to the gate, drawing lightning into the gate and allowing them to dial out by rotating the ring manually.
- Naked People Are Funny: The glomping scene when Ernest sees real people again after over fifty years. He has long since dispensed with the need for clothing due to the balmy climate the outpost is at. Carter quickly gets out of the line of sight when he beelines towards her and Teal'c during his glomping spree.
- Ominously Cut Tether: The last of Ernest seen in the video is his air hose cut off by the gate deactivating. Subverted in that he turns out to be alive, even though later details on gate operations suggest he should have been trapped in the gate buffer and erased the next time it activated.
- Series Continuity Error: In this episode, Catherine says that she was twenty-one in 1945, which would make her about four years old in 1928. In the original movie's flashback to 1928, she is clearer much older than that, around ten or so. Later on, Stargate Origins portrays her being around twenty in 1938-39, which is consistent with the movie, but inconsistent with "The Torment of Tantalus".
- Stay in the Kitchen: The attitude of Catherine's father and the 1940s military in regards to her interest in the Stargate. Although given his objection to her acting as a maid in one flashback scene, he ironically wanted her out of the kitchen in the literal sense of the term.
- Title Theme Drop: In the opening 1945 flashback, the background music is the Stargate theme played in the style of 1940s jazz.
- Wham Episode: Relatively subtly done by the standards of most such episodes, but this episode reveals for the first time that the Goa'uld didn't create the Stargate network when the SGC realise that the address Ernest dialled isn't on the Abydos cartouche, establishing that the Stargate network was built by someone else.
- What Happened to the Mouse?: The "true universal language" is never brought up again, even though they meet the aliens who made it.