“I reconnected with the child inside of me,” enthuses Choi, “all those films I watched in the cinema when I was in high school, like Alien, Back to the Future, The Terminator. I still remember how thrilled I was, the exhilaration. I couldn’t sleep for days because I was so happy.”

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It quickly becomes apparent that Choi is a huge science fiction buff whose knowledge and influences extend far beyond the Hollywood blockbusters of the 1980s.

He excitedly name-checks literary greats like Philip K. Dick and Arthur C. Clarke, specifically the latter’s third law, which states that “any sufficiently advanced technology is indistinguishable from magic”.

This is a motif that appears throughout Alienoid, as Taoist wizards from Korea’s distant past come into contact with futuristic alien technology they struggle to explain.

“To me, the science fiction world and traditional Korean fantastical world are quite similar in the end. [In Alienoid] the material world and the psychological world come together in a big explosion. That was the point I found the most thrilling,” he says.

With a budget of 33 billion won (US$25 million), Alienoid arrives as one of the most expensive South Korean movies ever made, but surely budgetary restraints can’t be the only reason for the local industry’s reluctance to venture into fantasy-film making?

“Yes, there is a reluctance to explore this genre because of the budget of course, but you can always make a good sci-fi film with a small budget,” Choi concedes, although he seems unsure about why this has been the case.

He adds: “There is also the lack of a long lineage of science fiction literature in Korea, even though lately there are some young writers who have written great sci-fi novels.

“I guess Korean creators and Korean film directors don’t have such a history or tradition to look to. But there are many Korean directors who want to make sci-fi films and are working on new projects. So there is definitely growth in the genre in Korea and it is definitely expanding.”

Choi suggests that the issue may simply be a hesitancy within the industry’s old guard to try something new. “These days Korean directors, especially emerging directors, are talking about science fiction quite a lot.

“Fifteen years ago there was a party, where 40 or 50 directors got together and we were all asking each other about our next projects. One young director said he wanted to make a zombie film, and the older generation said ‘No, don’t touch that genre. It’s never going to work’, and look what happened?!”

Choi is quick to deflect blame from his predecessors and mentors, however. “Don’t get me wrong, I’m not saying that the older generation discourages emerging directors from trying new things, I’m just saying that 15 years ago the general preconception was that high-concept films won’t work in Korea.

“But now there are so many high-concept films coming out of Korea that are definitely pushing the envelope, expanding the market and nurturing creativity too.”

“All the characters from the past – including those played by Ryu Jun-yeol and Kim Tae-ri – will travel to the present and complete their adventure there. Lee Hanee’s character will play a much bigger role, but in terms of additional characters or big names, I cannot reveal that right now,” he says.

“We still have 10 months of CGI work to complete,” he says and, with a chuckle, adds, “and my producer is staring right at me.”