American comic book artist Nick Spencer readily admits that the controversial twist in his Captain America: Steve Rogers #1 issue was a "gimmick".

In May, the 38-year-old sent shock waves through the comic book world when he wrote that Captain America, arguably the most honourable superhero, was in fact an undercover agent working for the evil Hydra organisation all along. Fans were so infuriated by the prospect that they sent Spencer death threats on social media.

But just one month later, it was then revealed that the new back- story has only the result of false memories - that is, some form of mind control.

Many fans felt that it was a huge cop-out on the part of Marvel Comics and, again, took to social media to vent.

In a one-on-one interview with The Straits Times, Spencer muses: "Aren't all stories kind of gimmicks? If you look at all the big stories in comic book history, such as the deaths of Spider-Man's girlfriend Gwen Stacy or Superman - everyone would say those were gimmicks.

"When people say that, they mean that it's something that gets a lot of attention and people talking. But that's really part of our job when we want to tell great stories."

Still, he is adamant that "this is not a gimmick in the sense that it is artificial in any way".

He adds: "This is a story that we've laid the groundwork for for a very long time and it's a story that has something to say about Captain America and the Marvel universe.

"Sometimes, crazy things happen in stories because maybe the publisher wants to make a quick buck. But that's not where this story came from."

He is in town to speak as a special guest at the Singapore Toy, Game & Comic Convention, which will be held at Marina Bay Sands today and tomorrow.

This year, the annual event celebrating pop culture will also put the spotlight on personalities such as Australian comic book writer Tom Taylor, Japanese manga artist Haruhiko Mikimoto and Italian arist Simone Legno, who is co-founder of the cult-favourite lifestyle brand tokidoki.

Later in the interview, Spencer adds that the whole Hydra agent storyline had been in the works for more than a year and that he chose Captain America because the character is the one that people "trust the most, so if you couldn't trust him anymore, the stakes are that much higher and would be great for conflicts".

When he first pitched the idea, he was almost sure that the bosses at Marvel would reject it.

"But they really liked it. I was pretty shocked myself," he says with a laugh.

"They were very supportive from day one, but I guess it's also because they had the luxury that the readers didn't, which is to see the whole story and where it's headed.

"By now, I think most of the readers are also understanding the story better and ready to go along for the ride. Not everybody, but most. For everyone else who is still upset, I apologise."