Star Trek: Discovery will visit Talos IV - home of the first-ever aliens in Star Trek. Introduced in the original Star Trek pilot episode, "The Cage", which was aired as "The Menagerie" two-parter in The Original Series season 1, the Talosians haven't been seen in any Star Trek TV series or movie since.

Star Trek was originally very different from the series that ultimately starred William Shatner as Captain Kirk. The first Star Trek pilot, "The Cage", starred Jeffrey Hunter as Captain Pike but NBC deemed the episode "too cerebral" for TV viewers in 1966. Instead of shutting down Star Trek straight away, the network ordered a second pilot; Star Trek creator Gene Roddenberry recast most of the key roles, leaving only Leonard Nimoy as Mr. Spock. Roddenberry then cleverly repurposed the footage of "The Cage" and turned it into "The Menagerie", which was about Spock defying orders to bring a critically injured Pike back to Talos IV.

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In Star Trek: Discovery season 2, episode 7, "Light and Shadows", Michael Burnham found Spock, her fugitive adoptive brother, hiding on Vulcan. Spock has been psychologically damaged by a vision of the Red Angel and spouted a series of numbers - 749-148 - which are coordinates to Talos IV, a destination Burnham and Spock set a course for after they escaped Section 31. This will be the third time fans will see Spock visit Talos IV, but in terms of continuity, it will be Spock's second visit since Star Trek: Discovery season 2 is set in 2257, 3 years after "The Cage" but about 10 years before the events of "The Menagerie".

The Talosians Were The First Aliens In Star Trek

Star Trek - The Cage - Talosian

Not counting the half-Vulcan Spock himself, the Talosians are Star Trek's first alien encounter. In "The Cage", the Starship Enterprise received a faked distress signal from the S.S. Columbia, which crashed on Talos IV in 2236. Pike soon learned the Talosians were a powerful race of telepathic humanoids who lived underground and they intended to keep the captain prisoner as part of their cosmic zoo; in fact, they needed Pike to breed with Vina, a human woman who was the lone survivor of the Columbia's crash.

Pike escaped the Talosians, leaving Vina behind, and after "The Menagerie", Talos IV was never seen in the franchise again. In fact, Talos IV is considered so dangerous that following Pike's encounter with the Talosians, Starfleet instituted General Order 7, which made any starship visiting Talos IV susceptible to the death penalty (it's the only death penalty in the Federation).

How Does Talos IV Tie Into Spock And The Red Angel?

Talos IV adds an intriguing to wrinkle to the mystery of the Red Angel, who visited Spock as a child and still haunts his nightmares, because the Talosians are extremely powerful telepaths capable of creating perfectly real illusions. They can even cast their illusions to other planets. Is the Red Angel working with the Talosians somehow? Are the Talosians responsible for the visions and nightmares Spock has endured since he was a child on Vulcan? Also, in "The Cage", the Talosians were only interested in Pike, not Spock, so perhaps Star Trek: Discovery will add previously unknown context to Spock's experiences on Talos IV. Spock may even believe that the Taloians' powers could help heal his fractured mind.

Related: Star Trek: Discovery Crippled The Enterprise To Explain A Plot Hole

It's also possible that by bringing Spock to Talos IV, Michael Burnham is risking the death penalty (if General Order 7 is already in place during Star Trek: Discovery's era). If not, what happens next between Spock, Burnham, and the Talosians could potentially become a further cause for Starfleet to institute the death penalty.

What Does A Return To Talos IV Mean For Captain Pike?

Captain Pike in Star Trek Discovery

Burnham and Spock are apparently going to Talos IV alone so unless Pike leads the Discovery to rescue them, the Captain won't have to revisit the traumatic events of "The Cage". It will still be a decade until the tragic delta-ray accident occurs that will turn Pike into a paraplegic and will motivate Spock and the Talosians to work together to return him to Talos IV. Spock and Michael's encounter with the Talosians could set the stage for how they will later work together to save Pike's life. And since this will be the first time the franchise has shown the Talosians since 1967, it will be fascinating to see how the inhabitants of Talos IV are depicted with Star Trek: Discovery's incredible visual effects.

Next: Star Trek: Discovery's Kelpien Conflict References Multiple TOS Episodes

Star Trek: Discovery streams Thursdays on CBS All-Access and internationally the next day on Netflix.