The stardate is 2179.3. Enterprise is orbiting an M-class moon (later seen labelled Sigma-287D). In Star Trek, M-class (or as established in ENT, Minshara-class) means it is generally Earth-like or habitable by oxygen-breathing humanoids with minimal assistance.
Kirk was stabbed by La’An while she was in the thrall of whatever was aboard the USS Griffin (SNW: “The Griffin Incident”). Coradrazine is a powerful stimulant, which in small doses can save lives, but in large doses can cause psychosis and paranoia (TOS: “The City on the Edge of Forever”), as M'Benga says here. In that episode, Kirk questioned McCoy’s use of cordrazine on a wounded Sulu, indicating he was familiar with its effects. We see here his first encounter with the drug.
La’An had a romantic interlude with an alternate timeline Kirk in SNW: “Tomorrow and Tomorrow and Tomorrow”, and while Prime Kirk and her shared a connection in SNW: “Subspace Rhapsody”, he was in the “on-phase” of his off-and-on relationship with Carol Marcus at the time. Now, however, both of them are single - La’An ended her relationship with Spock in SNW: “Level-Five Transporter Accident” and Kirk was ghosted by Carol at the end of “The Griffin Incident”.
Altairans are presumably from the Altair system. The star is also known as Alpha Aquilae, part of the constellation Aquila (meaning “eagle”) and in Trek lore has at least six planets. Altair VI is inhabited in TOS: “Amok Time”, and is the origin port for Kobayashi Maru (ST II). Altair III and IV were mentioned in TNG: “Encounter at Farpoint” and DS9: “Prophet Motive”, respectively.
Cadet A’Sha is with the landing party. Uhura mentions that once inside the cave, they’ll lose comms and the ability to transport. Beckett Mariner, who hates caves, sarcastically mentions in LD: “Caves” how rocks can successfully block centuries of technological process, and in LD: “Mining the Mind’s Mines”, she said that it’s not a real day in Starfleet until comms get blocked. How the SOS signal can get through if comms are going to be blocked is a question I leave for the interested viewer.
La’An’s diver’s watch is from the alternate timeline mentioned, and was worn by the alternate Kirk c. 2023.
The Klingon War took place during Season 1 of DIS, from 2257-2258. The USS Constitution, NCC-1700, was seen on a chart of ships undergoing repair at Starbase 11 in TOS: “Court Martial”, and presumably is the class ship for the Constitution-class starships of which Enterprise is one. This is the first time it’s been mentioned in on-screen dialogue, her other appearances to date being only in production and background art. Beta canon goes more into the ship’s story.
This is the first appearance of ADM Simon Reeger, played by Joe Morton. Ortegas is said to have helmed Pelanque during the war, presumably named after the Mayan ruins in Southern Mexico. Enterprise was at the Prospero system in SNW: “Under the Cloak of War”, where it was mentioned that Ortegas was stationed near it during the war.
This is the first mention of the Vaardan Massacre, an unprovoked attack that caused 5 million casualties.
Scotty mentions a cloaking system and refers to the Klingons using them. In DIS, the Klingons did use cloaks, which led to somewhat of a tizzy in fan circles because the impression was that cloaks where only used by Romulans at that point and in TOS: “Balance of Terror” the crew did not seem familiar with cloaks. I won’t get into it now, except to say that like many things, fan perception of what is canon isn’t as strong as they might imagine.
Ortegas says that during the Cold War, destroyers would follow enemy submarines via their trash. In the 1965 movie The Bedford Incident, the destroyer Bedford figures out that a Soviet sub they are hunting has been in the water for about 36 hours by analysing the thickness of the potato peels in the garbage it left behind.
The screen shows the mystery ship heading off in the direction of the Romulan Neutral Zone, which implies heavily that it might be Romulans who are responsible. The idea of tracing it via the emissions of its impulse engines also harkens back to Scotty’s line in “Balance of Terror” that the Romulan ship’s power is “simple impulse”. The incident in “Balance”, however, will not occur for another 3 or 4 years.
ADM Reeger commandeers Enterprise, presumably under Starfleet Order 104, Section B, paragraph 1(a) (TOS: “The Doomsday Machine”).
Enterprise warps out of orbit at Warp 5. The show has not really been consistent as to exactly when it is dangerous to go to warp while within a planet’s gravity well, or even a star system’s, although fan lore has long held that it is shouldn’t be done.
Zeta Reticuli is a real binary star system (consisting of Zeta-1 and Zeta-2 Reticuli) about 39 ly from Earth. It first appeared in a chart in ENT: “Cold Front”. In UFO lore, it is allegedly the home of the Grey aliens, also known as Reticulans.
George Samuel Kirk, Sr. is Jim and George Jr.’s father, who was played by Chris Hemsworth in Star Trek (2009), where he was first officer of the USS Kelvin in 2233. In the novel Final Frontier by Diane Carey he was first officer under Robert April on the maiden voyage of Enterprise.
Argus II could be related to Gamma Argus II, which was listed in production art in TNG: “Conspiracy”. The map on Ortegas’ console shows a system of four planets.
General Order 24 (TOS: “A Taste of Armageddon”) orders the destruction of “the entire inhabited surface of [a] planet.” Its mention here settles a long fan debate about whether Kirk was making it up when he ordered Scotty to implement it in “Armageddon”.
Increasing phaser power by routing it through the warp core became part of Enterprise’s design when it was refitted following the five-year mission (TMP).
Nadions are particles emitted when energy weapons like phasers or disruptors are used. The TNG Tech Manual says that nations can disrupt nuclear forces and free atomic nuclei. Nadion radiation can be fatal (VOY: “Nothing Human”) or used to slow the progress of a disease (DS9: “Extreme Measures”).
The Andorian leader, Tuur, says he has no love for Vulcans. In the 22nd century, Vulcans and Andorians were in a near constant state of hostilities (ENT: “Shadows of P’Jem”). Tuur is played by Currie Graham, who also acted in the Star Trek fan production Of Gods and Men.
As stated in “The Doomsday Machine”, if a medical officer certifies the commander medically or psychologically unfit, they may be relieved under Order 104, Section C.
Reeger's line, "And when that ship attacks again — and it will — the blood, the terror, will be on your head," is also another allusion to "Balance of Terror".
Pike tells Uhura, “You can do everything right, and sometimes things still don’t work out the way we hoped.” This echoes Picard’s advice to Data in TNG: “Peak Performance”: “[I]t is possible to commit no mistakes and still lose. That is not a weakness. That is life.”
Hemmer was Enterprise’s Aenar engineer, who Uhura referred to earlier in conversation with Tuur, and who sacrificed himself in SNW: “All Those Who Wander”.
The script seems to want to excuse George Kirk Sr.'s stalled career and absence as a parent when the brothers were growing up to Reeger's sabotage, but if that malice only dates back to the Klingon War and the Battle of Zeta Reticuli, it's only been about 4 or 5 years since the war ended.
This may be the first episode this season not to be a clear genre homage (although Crimson Tide would do), but "badmiral" episodes are a staple in Star Trek.