Talosian singing plant
Talos star group
Talos IV was the fourth planet of the Talosian system. An inhabited M-class planet, this was the homeworld of the Talosians, a telepathic humanoid species, as well as of the Talosian singing plant. The planet had an atmosphere of oxygen-nitrogen and a gravity that was 0.9 of Earth standard.
Talos IV had no moons and was located in the Talos star group within the Alpha Quadrant. Located three astronomical units from the binary stars Talos A and Talos B, Talos IV had a highly inclined orbit that brought it close to the orbit of Talos V.
After thousands of years had passed since war had devastated the planet, Talos IV was beginning to support life again in the mid-23rd century. By then, the planet's deep underground had been inhabited by the Talosians, who had evolved as an old and weakened species with enormous mental powers. In 2254, the planet was visited by the Federation starship USS Enterprise – under the command of Captain Christopher Pike – after receiving a distress call from the SS Columbia, which crash-landed there in 2236. However, the only survivor of this crash was Vina, a female Human. (TOS: "The Cage")
In 2267, Talos IV was revisited by the Enterprise while commandeered by Spock, in order to deliver Captain Pike there. Pike had been crippled by delta rays but was able to live a normal life on the planet, together with Vina. (TOS: "The Menagerie, Part II")
In the original story outline for "The Cage" (as fully reprinted in the reference book The Making of Star Trek, pp. 47-65), Talos IV was named Sirius IV and was inhabited by crab-like aliens who kidnapped Captain Robert April. The outline additionally describes the surface of Sirius IV as "arid, rocky" and "the arid waste."
The Talos IV set was designed by art directors Franz Bachelin and Pato Guzman. The set included a massive painted backdrop that greatly enlarged the set's apparent size. Although the sky pictured in the backdrop was a cloudy gray, Director of Photography William E. Snyder and the production crew gave the sky a slight greenish tint using colored lights, thereby making the planetscape seem more alien. ("The Menagerie, Part II" text commentary, TOS Season 1 DVD) The Talosian elevator created as part of the set was built on a platform, allowing the lift to descend without necessitating excavation below the soundstage's floor. ("The Menagerie, Part I" text commentary, TOS Season 1 DVD)
The position of Talos IV was implied in "The Explored Galaxy", a map of charted space in the Alpha Quadrant that was shown multiple times in Star Trek. On the map, Talos was located between the Tholian Assembly and Romulus. Both locations were identified in DS9: "The Search, Part II" and "Call to Arms" as being located in the Alpha Quadrant. This chart was also seen in several Star Trek: The Next Generation and Star Trek: Deep Space Nine episodes set in the 24th century, from the year 2364 to 2370. These were: TNG: "Conspiracy", "The Measure Of A Man", "The Emissary", "The Mind's Eye", "The Game" and DS9: "In the Hands of the Prophets" and "Cardassians".
According to the book Star Trek: Star Charts (p. 34), Talos IV was a non-aligned planet in 2378. Also, information on the planet's official name, government, capital city and population were unavailable to the Federation in that year.