|Original air date|
|Atlantis Season 2|
|Season 1||Season 3|
Lt. Colonel John Sheppard is sucked through the event horizon of an entrance to a cave, and cannot get out the same way. Worse, there is a Time dilation field, meaning that minutes in relative conditions could mean hours for Sheppard. If they don't find a way to save him soon, he is going to die of old age.
While scouting a planet by Puddle Jumper, the team notices what appears to be a massive crater on the surface. Dr. Rodney McKay asks to check out the rim of the crater as he has detected energy readings, but once they get there, all they find is a doorway and some Ancient writing. However, the energy readings are coming from the doorway. Just to be safe, McKay ties a camcorder to the end of a stick and puts it through the door, discovering an energy barrier that it must pass through. He then pulls it out and deduces that the other side appears safe, allowing Lt. Colonel John Sheppard to pass through. A problem arises, however, when Sheppard is unable to pass back through the doorway, and suffers injuries from the stresses of the barrier. What is more troubling, though, is that time within the barrier seems to be passing much faster than time outside the barrier, which Rodney failed to realize until further review of the tape after Sheppard passed through. Sheppard could already be starving to death. McKay, Ronon Dex, and Teyla Emmagan quickly toss all their supplies through the portal. Then McKay departs for Atlantis to get help — before Sheppard dies of old age.
Indeed, inside the portal, days have passed. Trapped in a cave without food, water, or word from his team, Sheppard is discouraged. The arrival of the supplies helps, but when more days pass with no further contact, he's forced to seek food elsewhere. He discovers that, on the other side of the immense mountain range above him, the cave opens into a verdant valley. Unexpectedly, a man races up to him, shouting frantically about a beast. Then the beast — a semi-invisible monster — attacks them both, knocking Sheppard unconscious.
He awakens in a tranquil village. The man, Avrid, and his sister, Teer, explain that the Ancients created this valley as a place for people to meditate on spiritual truths and, eventually, Ascend to a higher plane of existence. To Sheppard's horror, they add that, except by Ascending, no one can leave the valley. Ever.
Weeks turn into months as, with Teer's help, Sheppard struggles to adapt to his new life. Then, one day, the mysterious beast attacks the village. To Sheppard's disgust, the villagers hide, leaving him to face the creature alone. He barely survives. Feeling abandoned by his teammates and now by the passive villagers, the deeply frustrated Sheppard tries to make his new friends understand that Ascension won't mean much if they're mauled to death before they can achieve it.
Meanwhile, outside the barrier, only a few hours have passed and the team has returned. Although a probe sent through the field is destroyed, it locates the power source of the field and McKay also concludes that time in the field passes about 250 times faster than in real time, which would mean that a single hour in real time would equate to at least 10 days within the field.
Inside the field, Teer confidently responds that her lifetime of spiritual practice has given her clairvoyance. This power warns her that the beast will attack Sheppard's team. But this time he gets help from the villagers who have realized that the beast is only a manifestation of their fears. Now that they have realized this they all ascend – and although they extend an offer to join them, Sheppard declines. Teer then turns to McKay, advising that he not remove the ZPM, for it must remain for others to use. However, they will open the barrier for them to leave.
Ancient; Ancient language; Ascension; Atlantis; Lt. Laura Cadman; Camcorder; Canteen; Cast Away; Conan; Energy bar; FN P90 Personal Defense Weapon; Gas giant; Healing power; Lightning; M9 pistol; MALP on a Stick; Particle magnum; People of the Cloister; Planet of the Cloister; Precognition; Puddle Jumper; Radio; Sanctuary Beast; Skirmish with the Sanctuary Beast; Telekinesis; Telepathy; Time dilation field; Volleyball; Water; Xena; Radek Zelenka; Zero Point Module
McKay: Why do you have to park SO far away?
Sheppard: This ridge is a little farther away that it looked. You can't just land a Jumper anywhere Rodney.
McKay: It doesn't matter now, I think we're almost there.
Teyla: Rodney, do you even know what it is we are looking for?
McKay: Yeah, well whatever it is, it's around here somewhere.
Ronon: What's around here?
McKay: Whatever it was that was causing the energy spike we detected from the Puddle Jumper.
Sheppard: Any idea what that looks like?
McKay: I'll know it when I see it...and I see it.
McKay: Yeah – I would just like to be able to explain these readings better before we step through. Get me a branch. You got tape? Because I got a camera! (Ronon gives him a huge branch) I didn't ask for a log! (Teyla brings him a better one) Thank you! Okay, so tape it to the stick, we extend the camera through, record for a few minutes, pull it back, play the recorder.
Sheppard: Yeah! MALP on a stick!
McKay: Yes, MALP on a stick. Very clever. Are we done?
McKay: To a higher plane of existence. The race of people who built the Stargates -- they eventually evolved to a point where they ascended to a state of pure energy.
Ronon: That'd be great!
McKay: Yeah, well, sadly it's a matter of, uh, evolution. Anyway ... I'm sure we've got more than enough now. (He pulls the camera back through the doorway.) There we go. And ... have a look, shall we?
McKay: Just back out if you encounter anything problematic.
McKay: Yeah, like poisonous atmosphere, acid atmosphere, no atmosphere - hey, it's MALP on a stick, only shows you so much.
Weir: And why not assume that he'll make his own way back through the portal?
McKay: Because Colonel Sheppard would have already had hours to try to make it back through the portal in the time I wasted explaining the situation to Conan and Xena!
Sheppard: Thank you.
Teer: It is we who should thank you for saving our brother from The Beast.
Sheppard: That's funny, I don't remember winning.
Ronon: You wanna pick up the pace, McKay?
McKay: Hey, he's waited for months, another half-hour isn't gonna kill him.
Weir: Well, we don't know how long it's gonna take to find him.
Beckett: Aye, and besides I have a date planned with Lieutenant Cadman for tomorrow night.
McKay: Oh no, so we've only got twelve years in here.
- From Sheppard's perspective, this episodes takes place over the course of approximately six months. However, for the other Atlantis personnel, it takes place over the course of about 2 hours.
- The start of this episode uses a short piece of stock footage from "Childhood's End" of the Puddle Jumper flying over a pond.
- This episode bears comparison to the Stargate SG-1 episode "A Hundred Days" in which Colonel Jack O'Neill is stranded on an alien planet for three months and becomes part of the local society.
- Dr. Rodney McKay's comment about Lt. Colonel John Sheppard and ascended women is a reference to Chaya Sar, from "Sanctuary".
- Dr. Carson Beckett says that he has a date with Lt. Laura Cadman. This is a reference to the episode "Duet".
- At one point, Sheppard says into his radio, "This is Sheppard. I'm pretty sure you can't hear me, but I don't have a volleyball to talk to, so what the hell." This is a reference to the movie Cast Away, in which Tom Hanks is stranded several years on an uncharted island, and spends his time talking to a volleyball he names Wilson.
- The idea of a monster created from the subconsciousness of human beings with enhanced mental powers is rather similar to the plot of the classic sci-fi movie Forbidden Planet. The plot also resurfaces in a Star Trek: Deep Space Nine episode "The Storyteller", though in that episode, the creature was created with a spiritual object.
- The basic plot concept of a team member spending a disproportionately large amount of time in an alien culture while the rest of the team tries to quickly save them is similar to the Star Trek: The Next Generation episode of "The Inner Light" where Picard spends a lifetime in a virtual reality created by an alien probe.
- The invisible monster appears in a similar manner to the monster in Star Trek: The Next Generation episode "Darmok".
- McKay said that 3 seconds outside the field was equal to 12 minutes inside, and Teyla said that meant time was passing 250 times more quickly, but using those numbers, it was really 240.
- Ronon Dex's sword differs this episode onwards. It may be a completely different sword that he owns, the Wraith may have altered it after his capture on the hive, or it may just be a back-up prop, but the handle is wrapped in what appears to be a leather material, rather than the Wraith hair normally braided around it.
- It is most likely another sword as when they leave the hive Ronan only gets his gun back the sword was most likely left behind.
- McKay called Ronon "Conan" which is amazing foresight by the writers as Jason Momoa played Conan in the 2011 movie Conan the Barbarian
- When the villagers ascend at the end of the episode, they do not leave their clothes behind. This differs from every other time a person is seen ascending in the Stargate franchise.
- This is the first episode of the Stargate Atlantis series not to feature a Stargate.
- Joe Flanigan (Lt. Colonel John Sheppard) helped write this episode. Joe originally pitched a story where Sheppard and McKay find themselves being treated like kings while on a mission. That idea was rejected because the plot had been used for the Stargate SG-1 episode "It's Good To Be King." His second pitch was spun into "Epiphany." It is the first of two episodes written by Flanigan.
- This is the only episode of Stargate: Atlantis directed by Neil Fearnley.
- David McNally (Avrid) previously played Hanno in the Stargate SG-1 episode "Cor-ai" and Simon in the episode "Demons".
- Nicole Muñoz (Hedda) is best known for playing Christie McCawley on Defiance.
- Dr. Rodney McKay said that one hour would give them months inside the field. This is incorrect because the ratio of time is 1:250 which would give them 250 hours in the field which is only ten days and ten hours.
- Lt. Colonel John Sheppard is seen using an Colt M1911A1 pistol when shooting the event horizon, but later, when fighting the Sanctuary Beast, is using the standard issue M9 pistol.
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