Star Trek is one of the most beloved franchises in sci-fi history. The original series ended in 1969 after just three seasons and 79 episodes, but it was followed by Star Trek: The Next Generation, which aired from 1987 until May 1994. One of its early episodes, Conspiracy, was the penultimate episode of TNG's first season and the premise featured a parasitic alien race attempting to take over Starfleet's strategic section. However, the episode was banned by the BBC for being "too violent." This was down to a particularly graphic scene of a possessed officer, Remmick, exploding and melting.

According to Screen Rant, the BBC banned the episode outright when it first aired. Producers Rick Berman and Peter Lauritson later said in a documentary that they were concerned about Conspiracy being too dark.

The BBC eventually aired Conspiracy in 1991, but several minutes of footage, including most of Remmick's graphic death scene, were removed from the episode.

To see how children would react to the episode, producers Berman and Lauritson showed Conspiracy to a supervisor's six-year-old son. He apparently reacted, "I really liked the part where the guy's head blew up! You know, you could make a Remmick action figure where if you pressed the button, his head blows up!"

When it aired in Canada, a viewer discretion warning was required. According to MovieWeb, the most violent scenes were so convincing that they won the show the Best Makeup vote at the 40th Primetime Emmy Awards.

The original Star Trek series premiered on September 8th, 1966. The programme made almost immediate stars of its main cast members like William Shatner and Leonard Nimoy. Leonard, who died in February 2015 at the age of 83, played the role of Spock.

However, only dedicated Star Trek fans would know that Leonard was not actually the first choice to play the fictional character. Screenwriter Gene Roddenberry originally had cast Leonard as the lead actor for Spock, but then was told to give other actors a chance to audition.

Two actors were offered the role before it was eventually given to Leonard Nimoy. Co-star DeForest Kelley, who would eventually play Dr. Leonard "Bones" McCoy, and Martin Landau were individually offered the chance to play the character.

In an extract of William Shatner's book, Star Trek Memories, he wrote about Gene speaking to DeForest, who accidentally confessed that he was offered the role of Spock first.