Warning: SPOILERS for Star Trek: Discovery Season 4, Episode 7 - "...But To Connect".
The USS Discovery is poised to break through the Galactic Barrier in Captain Michael Burnham (Sonequa Martin-Green) and her crew have been trying to unravel this massive new threat to the United Federation of Planets. After many attempts to learn what the DMA is, Discovery's best minds determined that the anomaly originated from outside of the galaxy and beyond the Galactic Barrier.
In Star Trek: Discovery season 4, episode 7, "...But To Connect," Zora (Annabelle Wallis), the USS Discovery's sentient artificial intelligence, successfully calculated the coordinates of the DMA's origin point. Zora initially refused to disclose the coordinates to Discovery's crew because of the imminent danger traveling across the Galactic Barrier would place them in. Meanwhile, Federation President Laira Rillak (Chelah Horsdal) called an assembly to debate and vote on the best course of action against the Dark Matter Anomaly and its mysterious creators, Unknown Species 10C. Although Roun Tarka (Shawn Doyle) created a weapon that could destroy the DMA and Book argued for immediately eliminating the threat, Captain Burnham urged the Federation to vote for a diplomatic response instead. Diplomacy won out, but Tarka and Book went rogue and left Discovery to deploy their weapon against the DMA on the other side of the Galactic Barrier.
With this new twist in Star Trek: Discovery season 4's DMA storyline, Burnham and her crew will travel someplace completely new for the first time, which fulfills Star Trek's core mandate of exploring strange new worlds and seeking out new life and new civilizations. Although Captain James T. Kirk's (William Shatner) Starship Enterprise crossing the Galactic Barrier before, each sojourn was brief and neither Kirk nor Star Trek has explored what, exactly, was on the other side of the Galactic Barrier. For Star Trek: Discovery, what lies beyond the Great Barrier is truly the great unknown for season 4.
Star Trek's Galactic Barrier Explained
The Galactic Barrier was introduced in the second Star Trek pilot, "Where No Man Has Gone Before." The Galactic Barrier is an energy field surrounding the rim of the Milky Way Galaxy. It's invisible to sensors and to the naked eye but up close, the barrier emits a purple-to-pinkish wave of negative energy. Although no known transmission can through the Barrier, Starfleet ships powerful enough have been able to cross it at great risk. The first known instance of an Earth vessel breaching the Galactic Barrier was the SS Valiant, which was swept into the energy field by a magnetic storm in 2065. Although it is only occasionally seen or referenced in Star Trek, the Galactic Barrier has been an important part of Trek canon since the very beginning.
The Galactic Barrier shouldn't be confused with the Great Barrier, which is located at the center of the Milky Way Galaxy. The Great Barrier is a similar energy field to the Galactic Barrier. Beyond the Great Barrier lies the fabled world of Sha-Ka-Ree, which is where Spock's older brother Sybok (Lawrence Luckinbill) believed God resided in Star Trek V: The Final Frontier, However, "God" was revealed to be a malevolent alien being that needed a starship to escape Sha-Ka-Ree so it could conquer the galaxy, and it was destroyed by Spock (Leonard Nimoy).
All 3 Times Kirk's Enterprise Crossed The Galactic Barrier In TOS
Captain Kirk's Starship Enterprise penetrated the Galactic Barrier in Star Trek: TOS' second pilot, "Where No Man Has Gone Before." The strange energies of the Galactic Barrier transformed Lt. Commander Gary Mitchell (Gary Lockwood) and Dr. Elizabeth Dehner (Sally Kellerman), who both had heightened ESP capabilities. Mitchell and Dehner developed powerful psychic abilities and became a threat to Kirk's Enterprise. After exiting the Galactic Barrier and returning to the Alpha Quadrant, Kirk confronted Lockwood and Dehner on the planet Delta Vega, where both psychics died after a battle with the Enterprise's Captain.
Kirk's Enterprise ended up crossing the Galactic Barrier in every season of Star Trek. In the TOS season 2 episode "By Any Other Name," Kirk and the Enterprise encountered Kelvans from the Andromeda Galaxy, who crossed the Galactic Barrier and became stranded in the Alpha Quadrant. Kirk's crew eventually foiled the Kelvans' plan to hijack the Enterprise and cross the Galactic Barrier back to the Andromeda Galaxy. In the Star Trek: TOS season 3 episode "Is There No Truth In Beauty," Federation engineer Larry Marvick (David Frankham) was driven mad by glimpsing a Medusan, and he stranded the Enterprise in a space-time continuum void deep within the Galactic Barrier.
Picard Season 1's Villain Is From Beyond The Galactic Barrier
Star Trek: Picard season 1's finale, the synthetic beings have tentacled arms and they intended to wipe out all organic life in the galaxy. However, the synthetic villains used a wormhole to enter the Alpha Quadrant that Jean-Luc Picard (Patrick Stewart) and his ragtag crew managed to close, rather than cross through the Galactic Barrier into Federation space.
There have been other Star Trek villains who have come from another galaxy, such as the robot planet killer in the Star Trek: TOS episode "The Doomsday Machine." Spock determined the Doomsday Machine's trajectory originated from outside our galaxy. This means the planet-killer likely crossed the Galactic Barrier to enter the Alpha Quadrant, and it's possible the Doomsay Machine's origins may even have ties to the Dark Matter Anomaly and Unknown Species 10C.
What Crossing The Galactic Barrier Means For Discovery
Unlike the Starship Enterprise, the USS Discovery doesn't actually have to cross the Galactic Barrier to get to the other side. The Discovery's spore displacement hub drive will let Captain Burnham's ship instantaneously jump to the coordinates Zora provided, although Tarka and Book have a head start thanks to the next generation spore drive the mad scientist installed on Book's ship. It sets up an interesting conflict since Burnham, who is mandated to wave the flag of peace towards Unknown Species 10C, now has to simultaneously stop Book and Tarka from potentially instigating an extragalactic war if they successfully destroy the DMA.
Star Trek: Discovery's one-way time jump to the 32nd century afforded the series the unique opportunity to trailblaze new canon for the franchise since so much of Star Trek's 23rd and 24th century has already been definitively established. While The Burn storyline of Star Trek: Discovery season 3 reintroduced the broken Federation and alien species, familiar and new, to Michael Burnham and Discovery's crew, Star Trek: Discovery season 4's DMA story is a long-awaited opportunity for Starfleet and the audience to finally see what lies on the other side of the Galactic Barrier. It's a chance for Star Trek to hopefully introduce new concepts and ideas that aren't limited by what's already been defined in the Alpha Quadrant. Trekkers' fingers are crossed Star Trek: Discovery delivers something new and genuinely fascinating when Burnham and her crew come face-to-face with Unknown Species 10C.
Star Trek: Discovery streams Thursdays on Paramount+.