The title literally translates from Latin as “A voice on high”, and is the title of papal declaration (or bull) issued by Pope Clement V on 22 March 1312 formally dissolving the Knights Templar. It is therefore associated with declarations from lofty authorities.
The opening production titles are a combination of English and Klingon letters: “mutlh CBS Studios malja’”, which translates as “CBS Studios business construction”, a rough approximation of “A CBS Studios Production”.
The stardate is 868943.8, which makes it late 3191, some weeks after the previous episode. The Val Nebula makes it first appearance in lore, although similarly named nebulae include the Volterra Nebula (TNG: “The Chase”) and the Vaultera Nebula (SNW: “Ghosts of Ilyria”).
There is a sign advertising the Bajor Club, the Celestial Temple. The Bajorans worship alien entities they call the Prophets, who live inside a stable wormhole they term the Celestial Temple, central to the premise of DS9.
The Doctor quotes from (as Genesis correctly identifies)Judge Aaron Satie, a passage first recited by Picard in TNG: “The Drumhead” as a warning against small infringements of liberty which can lead to tyranny. The full quote is, “With the first link, the chain is forged. The first speech censured, the first thought forbidden, the first freedom denied, chains us all irrevocably.” Oddly, the Doctor skips the words “…the first freedom denied, chains…” which makes the sentence a bit unintelligible.
Klingon mating rituals were described by Worf in TNG: “The Dauphin”: “Women roar. Then they hurl heavy objects. And claw at you. [The man] reads love poetry. He ducks a lot.”
The Doctor is correct from a certain point of view. If not for his demands for autonomy and to be recognised as a member of Voyager’s crew, he may not have developed his sentience to the point where he could truly be called an intelligent being. Betazed rejoined the Federation in SFA: “Vitus Reflux”.
The Sigma Draconis system first appeared in TOS: “Spock’s Brain” and was mentioned in DIS: “Die Trying”.
SuvwI’ tlhIq does translate as “warrior stew”.
Caleb summarises a core part of the Klingon creation myth, the defeat of the tyrant Molor by Kahless, first told in TNG: “Rightful Heir”.
The Taurus system first appeared in TOS: “The Galileo Seven”, and more recently as a holoprgram in Star Trek Scouts “Holodeck Rescues, Part 2”.
The Klingon Empire and the Federation were suspicious of each other in the 22nd century, then wartime foes and adversaries in a cold war in the 23rd century, then allies through much of the 24th century. The Burn caused dilithium connected to active matter/antimatter reactors to fail suddenly, with explosive effect.
It is not surprising that the Klingons might have been heavily utilising dilithium-based reactors - overconsumption of energy is what caused the Klingon moon Praxis to explode in 2293 (ST VI), which precipitated the ecological crisis that resulted in the Klingons suing the Federation for peace and the two becoming allies. However, this time the Klingons appear to be refusing help. In DIS: “Scavengers” (c. 3189) a starchart was seen on a wall at Federation HQ showing quite a large “Klingon Zone” of space. This development now explains why it was not labelled as the Empire.
Krios (as a planet) was first mentioned as a Klingon colony in TNG: “The Mind’s Eye”. Subsequently the name Krios was used for another world which was in a war with Valt Minor (TNG: “The Perfect Mate”). This latter planet and the Kriosians showed up in ENT: “Precious Cargo” where it was referred to as Krios Prime. The appearance of Krios Prime here might be an attempt to reconcile the latter planet with the Klingon colony of the former.
“Beware of Klingons bearing gifts,” is a play on the old Latin proverb “Beware Greeks bearing gifts,” from the Aeneid, an allusion to the story of the Trojan Horse. McCoy does something similar in ST II when he gifts Kirk with a bottle of Romulan ale on the latter’s birthday with the phrase, “Beware Romulans bearing gifts.”
HurwI’ is the Klingon word for bow.
The new seat of the Federation government is to be built on Betazed, as per the agreement in “Beta Test”. The Emerald Chain is a 32nd crime syndicate made up of Andorians and Orions which was the main antagonist of DIS Season 3. This is also the first mention of Hectaron and its associated conspiracy theory in lore.
“Night Bird” was a jazz song which Riker struggled to master in TNG: “Second Chances” (and mentions again in LD: “Kayshon, His Eyes Open”). I don’t know if this nightbird mentioned by Jay-Den is related.
Klingon blood is usually seen as red. It was pink in ST VI more as a sop to the MPAA rating rather than something they wanted to do, but red or pink, black isn’t a good colour for it.
The ritual Klingon death chant (TNG: “Heart of Glory”) is supposed to warn the afterlife that a Klingon is on their way.
Veqlargh toQ translates to “Fek’lhr bird of prey.” Fek’lhr is the mythical guardian beast of Grethor, the Klingon underworld for the dishonoured, i.e. Hell as opposed to the Valhalla of Sto’vo’kor.
“Ah pè Kè pè Ulh pè cha” is a Khionan chant while “battle breathing”. Combat tactical breathing (or box breathing) is a technique used by the military, athletes and first responders to regulate stress and regain control and focus, although there is not usually an accompanying chant - inhale for a count of four, hold for a count of four, exhale for a count of four, hold for a count of court then inhale to start the cycle again.
The Organian Peace Treaty (TOS: “Errand of Mercy”) was forced on the Empire and the Federation by the Organians, and at some point between 2266 and 2285 it appears to have disappeared, to be replaced by a neutral zone between the two powers (ST II). What happened to the Organians has not been established in canon, but the DC Comics Star Trek series had them vanish from the galaxy together with the Excalbians (TOS: “The Savage Curtain”), leaving them unable to enforce the treaty. Eventually, the Khitomer Accords were negotiated starting in 2293 (ST VI), although the Empire did withdraw from them at one point (DS9: “The Way of the Warrior”).
Jay-Den’s insistence on Klingons being Klingons, retaining their identity, and the fear of losing that identity, has echoes of T’Kuvma’s “remain Klingon” conservative philosophies from DIS Season 1. T’Kuvma also feared that peaceful coexistence with the Federation would lead to an eradication of what he considered the Klingon identity, which is why he set up the Klingon-Federation War of 2257.
Lura says she comes from “freed” Jem’hadar lineage, which implies that at some point between now and the end of the Dominion War in 2375, the Jem’hadar (or at least some) were liberated from Founder and Vorta control, but retained their martial ways.
Vance says, “When the Klingon gods help us.” I was expecting Lura to correct him, because Klingons killed their gods - they were more trouble than they were worth (DS9: “Homefront”).
Athena’s bridge section separates from the main ship, much like the Galaxy-class is capable of disengaging the saucer section from the stardrive section (although it’s the latter that goes into battle rather than the saucer). The Starfleet vessels that join the fight are Capricorn, Crimson, Horizon, Lexington and Riker.
The Klingon battle music comes from Jerry Goldsmith’s classic TMP score. “Qap’la!” is of course Klingon for “success”, usually said before a battle or mission.