"The City on the Edge of Forever" is the 28th episode of the American science fiction television series "", and the penultimate episode of the .
 It was first broadcast in the United States on NBC on April 6, 1967.
 In the episode, after Doctor Leonard McCoy (DeForest Kelley) travels back in time and changes history, Kirk (William Shatner) and Spock (Leonard Nimoy) follow him to correct the timeline.
 In doing so, Kirk falls in love with Edith Keeler (Joan Collins), but realizes that in order to save his future, he must allow her to die.
The development of Spock, a fictional character first introduced in the American science fiction television series "", began prior to the start of the series.
 The first known mention of Spock was in a discussion between Gene Roddenberry and Gary Lockwood, where the latter suggested Leonard Nimoy for the role.
 Roddenberry agreed with the suggestion, and Nimoy became the first choice actor for the part.
 However, Roddenberry was required to audition other actors for the role.
 It was offered to both DeForest Kelley and Martin Landau before Nimoy, who accepted the part.
 The actor disliked the prosthetic ears he was required to wear, and there were concerns from the studio that they made him appear satanic.
 Roddenberry fought to keep the character in the second pilot, "Where No Man Has Gone Before" after the rest of the main cast was dropped from the initial pilot, "".
Star Trek III: The Search for Spock is a 1984 American science fiction film directed by Leonard Nimoy and based on the created by Gene Roddenberry.
 It is the third film in the "Star Trek" film series, and is the second part of a three-film story arc that begins with "" (1982) and concludes with "" (1986).
 After the death of Spock (Nimoy), the crew of the USS "Enterprise" returns to Earth.
 When James T. Kirk (William Shatner) learns that Spock's spirit, or katra, is held in the mind of Dr. Leonard "Bones" McCoy (DeForest Kelley), Kirk and company steal the "Enterprise" to return Spock's body to his home planet.
 The crew must also contend with hostile Klingons led by Kruge (Christopher Lloyd) who are bent on stealing the secrets of a powerful terraforming device.
Number One is a fictional character who, in "", the original pilot episode of the science-fiction television series "", was the unnamed intellectual, problem-solving second-in-command serving under Captain Christopher Pike.
 She performs the same role for Pike "as Spock later does for Kirk".
Spock is a fictional character in the "Star Trek" media franchise.
 Spock was first portrayed by Leonard Nimoy in the , and also appears in the , a two-part episode of "", eight of the "Star Trek" feature films, and numerous Star Trek novels, comics, and video games.
 In addition, numerous actors portrayed the various stages of Spock's rapid growth, due to the effects of the Genesis Planet, in the 1984 Star Trek film "".
 In the 2009 film "Star Trek", Nimoy reprised his role with Zachary Quinto, who depicted a younger version of the character, existing within an alternate timeline.
 Both reprised their roles in the 2013 sequel "Star Trek Into Darkness" and Quinto reprised his role again in 2016's "Star Trek Beyond".
Created by Gene Roddenberry, the science fiction television series "" (which eventually acquired the retronym "Star Trek: The Original Series") starred William Shatner as Captain Kirk, Leonard Nimoy as Mr. Spock, and DeForest Kelley as Dr. Leonard "Bones" McCoy aboard the fictional Federation starship USS "Enterprise".
 The series originally aired from September 1966 through June 1969 on NBC.
Star Trek Into Darkness is a 2013 American science fiction action film directed by J. J. Abrams and written by Roberto Orci, Alex Kurtzman, and Damon Lindelof.
 It is the twelfth installment in the "Star Trek" film franchise and the sequel to the 2009 film "Star Trek", as the second in a rebooted film series.
 The film features Chris Pine reprising his role as Captain James T. Kirk, with Zachary Quinto, Simon Pegg, Karl Urban, Zoe Saldana, John Cho, Anton Yelchin, Bruce Greenwood, and Leonard Nimoy reprising their roles from the previous film.
 Benedict Cumberbatch, Alice Eve and Peter Weller are also credited in the film's principal cast.
 It was the last time Nimoy would portray the character of Spock before his death in 2015.
 Set in the 23rd century, Kirk and the crew of USS "Enterprise" are sent to the Klingon homeworld seeking former Starfleet member-turned terrorist John Harrison.
Mind Meld: Secrets Behind the Voyage of a Lifetime is a 2001 American documentary film in which actors William Shatner and Leonard Nimoy discuss the "Star Trek" science fiction franchise and its effects on their lives.
 Shatner and Nimoy portrayed the characters James T. Kirk and Spock respectively in the , the , and their film sequels.
 They talk about differences they had with Gene Roddenberry, the creator of "Star Trek", and about the strained relationships between Shatner and some of the other cast members.
 It was in this film that Nimoy first publicly revealed that he had struggled with alcoholism while he was acting in the original television series.
 Shatner talks about the death of his third wife, Nerine Kidd, who accidentally drowned in a pool in 1999 after suffering from alcoholism.
Lionel Nimrod's Inexplicable World was a BBC Radio 4 comedy series starring Stewart Lee and Richard Herring (the comedy duo Lee and Herring), and narrated by Tom Baker as the title character Lionel Nimrod, an over-the-top parody of Leonard Nimoy.
 The show itself somewhat parodies the Leonard Nimoy program ""In Search Of..."".
 Over two series Lee and Herring tackled, and explained, such varying topics as Monsters, Love, The Human Body, and, finally, The Unexplained itself.
 Much of the comic material in the show was re-used on "Fist of Fun".
I Am Spock is the second volume of actor and director Leonard Nimoy's autobiography.
 The book was published in 1995, four years after the release of the last "Star Trek" motion picture starring the entire original cast, and covers the majority of Nimoy's time with Star Trek in general and Mr. Spock in particular.
 The book's title was a reference to the first volume of his autobiography, "I Am Not Spock", which had been published in 1975.
 At that time Nimoy had sought to distance his own personality from that of the character of Spock, although he nonetheless remained proud of his time on the show.
 Negative fan reaction to the title gave Nimoy the idea for the title of the second volume.

Question: Number One is said to perform the same role for Captain Pike as which Leonard Nimoy character did for Captain Kirk?
Answer: Spock