A Chance Meeting of Two Moons by Evilhumour (later joined by his beta-reader/co-author Anon eMouse Jr. is a My Little Pony: Friendship Is Magic fanfic, and the first in a planned series. Originally posted June 18 2014 to October 28, 2014, it was beta-read by Anon e Mouse Jr. in spring 2017, with updates posted later that year. A second round of revisions followed in November prior to the fic's continuation that same month.
As the story begins, Princess Luna goes to her private realm to vent after an argument with Celestia. Meanwhile, in his own dimension, Prince Artemis gets into a similar situation with his brother Solaris. Cue complicated relationships as the two opposite-gender counterparts meet and start to fall for one another.
A Chance Meeting of Two Moons contains examples of:
- Are You Pondering What I'm Pondering?: Twilight and Dusk Shine do this during their meeting. And as it happens, they are thinking the same thing.
- Big Bad: The mysterious voice that speaks to Pinkie Pie and Bubble Berry in chapter 13 is this, though their identity has yet to be revealed in-universe.
- Central Theme: In this story, it's synchronization.
- Cluster F-Bomb: Luna uses the Equestrian equivalent during her mental rant in chapter 12 (side Luna), technically making it a Cluster B Bomb.
- Everyone Knows Morse: Or at least, Dusk Shine does. Apparently, after "devouring the language portion of the library" as a foal, he would only speak in Morse code for a time, until Steel Barricade threatened to embarrass him by showing his Baron Von Genius Jeans action figure (his equivalent to Twilight's Smarty Pants doll) to everypony.
- Gale-Force Sound: Artemis's voice is sufficient to knock Solaris backward during an argument.
- Great Offscreen War: There was a war between Order and Chaos in the past, with a majority of the alicorns and draconequui of the multiverse fighting each other. This war is the reason why there are so few alicorns in the multiverse, and why the Doors to the Realms In Between have largely been sealed off.
- Hates Being Touched: Artemis, due to an incident in his past that involved mares (and was apparently his brother's fault), is very shy and doesn't like being too close to any mare who isn't Luna.
- Interrupted Intimacy: The times that Luna walked in on a drunken Discord and Celestia, and Artemis walked in on a drunken Eris and Solaris.
- I Say What I Say: Luna and Artemis do this when they first meet, and it happens again in chapter 5. Twilight and Dusk Shine later have the same thing happen when they meet. Celestia and Solaris also fall into it at one point, but only when they're flustered.
- Loud of War: Artemis, when extremely angry with his brother, turns on his music to very loud levels and leaves off the sound-muffling spells that would normally keep the noise confined to his own room.
- Noodle Implements: Apparently, Solaris once had drunken sex with Eris, and it involved a tuba and a banana. Likewise, Celestia with Discord, involving a tuba and a pineapple. Exactly how is never explained in either case.
- Not a Morning Person: Artemis, according to his brother. It's to be expected, given Artemis is generally nocturnal. Luna is the same way.
- Orwellian Retcon: In the fall of 2017, Evilhumour and Anon e Mouse Jr. went back and revised the earlier chapters, primarily to fix spelling and grammar, but also making a few other modifications. Among them included adding an earlier mention of the Doors to the Realms In Between (one had already existed later in the story), and changing one of Elusive's lines into a Big "YES!".
- Out-Gambitted: When Blueblood/Bluebelle tries to submit a proposal for a summer house he/she wants to build outside of Ponyville, Luna/Artemis sees it for what it really is - an attempt to set things up to establish a power base down there and make life miserable for the Element Bearers, and she/he immediately rejects it as a result. Later, when Blueblood/Bluebelle tries to convince Celestia/Solaris to their side, they are again made to look a fool by Luna/Artemis.
- Rule 63: A big part of the plot - Prince Artemis is from an alternate universe where the characters are the opposite gender from their canon selves. He himself is a counterpart of Princess Luna; Prince Solaris is the male counterpart of Princess Celestia, and others include Dusk Shine (male Twilight Sparkle), Elusive (male Rarity), Rainbow Blitz (male Rainbow Dash), Butterscotch (male Fluttershy), Bubble Berry (male Pinkie Pie); Applejack (male... Applejack), and Eris (female Discord). The only known exception is Starswirl the Bearded, who is male in both worlds.
- Screw This, I'm Outta Here!: When the six alicorns (Twilight, Celestia, Luna, Dusk Shine, Solaris and Artemis) catch Discord and Eris watching them in the dream realm and start raging at them, the two draconequui decide it would be best to make a run for it.
- Screw Yourself: Apparently, Celestia and her human counterpart have done this. Ditto for Solaris and his human counterpart, whom Solaris claims initiated it.
- Security Blanket: Literal example with Artemis, who tends to sometimes bury himself under a fortress of clothes and blankets in his closet.
- Switching P.O.V.: The story changes from Artemis to Luna's point of view (signaled by linebreaks) during the first five chapters. From chapter 6 on, there are two parallel versions of each chapter, one told from the POV of Artemis in Luna's world and the other from the POV of Luna in Artemis's world. Some of them even show the same sequence of events from the differing characters' point of view.
- Synchronization: Alternate universe counterparts can develop this; in Artemis and Luna's case, it ultimately leads to a full-blown Psychic Link, letting them speak telepathically to one another even from different worlds.
- Tantrum Throwing: Both Luna and Artemis start hurling plates and other things at their respective siblings when they start acting overprotective due to not being familiar with the other pony their younger sibling has just met.
- Thin Dimensional Barrier: The Door to the Realms In Between, which draconequui can open to allow them to visit alternate realms, including the dream world. A Chance Meeting of Two Moons marks its first appearance in Evilhumour's works; it's later mentioned in The Mare From the Moon as a sign that more worlds than these are connected.
- Trust Password: How Artemis and Luna confirm their identities as the others' counterpart from a parallel universe - they simultaneously reveal the time they each caught their older sibling having drunken sex with their world's draconequus.
- Worth It: Solaris reminds himself to make very irritating sunbeams for Steel Barricade's days off in retaliation for her taking pleasure in making sure he sticks to his diet, and thinks that having to deal with her afterward will be this.