There is no single breakout star in The Maze Runner movie franchise - but that is exactly why it works.

Unlike the two other currently popular young-adult dystopian film series The Hunger Games (2012, 2013, 2014) and Divergent (2014, 2015) - which made huge stars out of Jennifer Lawrence and Shailene Woodley respectively - The Maze Runner rides on the strong chemistry among the ensemble cast of rising young actors.

British actor Thomas BrodieSangster, who plays the kind but snarky Newt in The Maze Runner movies, tells Life he finds it "refreshing" that a big studio film franchise would take a chance on a group of relative unknowns.

He is joined in the cast by American actor Dylan O'Brien, 24; Korean-American actor Lee Ki Hong, 28; and British actress Kaya Scodelario, 23.

Brodie-Sangster, 25, muses: "They were thinking outside the box a bit in casting, I think, going for really interesting actors instead of just going straight for the big names.

"We're a bunch of actors who are really talented at what we do, but are just on the cusp of coming up. That, to me, was really cool."

Whatever potential the studio saw in this group of newbies, it was right. The Maze Runner, which is adapted from James Dashner's bestselling novel of the same name, was an instant box-office hit when it was released in cinemas last September, making more than US$344 million (S$491 million) worldwide.

Solid reviews also poured in, with many critics citing the all-around strong performance of and palpable chemistry among the cast, despite their youth and comparatively little acting experience.

In the new film, Maze Runner: The Scorch Trials, which opens in Singapore tomorrow, the group of friends have to stick closer together than ever as they deal with a whole host of other problems outside of the titular maze, ranging from extreme weather conditions to a mysterious virus known as The Flare.

Brodie-Sangster says: "The Maze Runner story is centred on a group of people who genuinely care for one another to survive and you can really feel that when you watch the film.

"It's seen to be strong, rather than weak, for the characters to all group together, and I like that a lot."

His co-star Lee, who plays the cool and supremely athletic Minho, believes that the much-lauded screen chemistry comes from how well the cast get along in real life.

He says: "We're all around the same age and this is a bunch of genuinely good and talented people, so it doesn't feel like work when we're filming.

"After every workday, we'll go to someone's hotel room and play Mario Kart and eat a lot of biscuits. There is a real sense of camaraderie and love and we're like one big family."

The cast is so tight-knit off screen that many of its members were guests at Lee's wedding, which was held in March in his native Los Angeles.

Much to the dismay of his growing teenage fangirl following, Lee tied the knot with his long-time Korean-American girlfriend Choi Ha Young.

It is easy, of course, to see his heart-throb appeal - his boyish good looks were given a boost by the uber macho characterisation of his movie role. Last year, he was listed on People Magazine's line-up of Sexiest Man Alive candidates.

But he has also become particularly popular among Asian audiences simply because of what he represents: that rare Asian leading man in a major Hollywood production who is not only cool but also utterly crucial to the story.

At the red-carpet premiere in Seoul last week, rabid South Korean fans thronged the mall it was held in, eager to catch a glimpse of him. Fans had camped out for good spots hours in advance, armed with gifts, banners and placards with his name emblazoned all over them.

A Taiwanese journalist who also attended this same press trip remarked that it would be unlikely that she or any of her fellow Taiwanese reporters would have travelled for the interviews if he had not been a part of the promotional trail.

Lee certainly does not take his special place for granted.

"As an Asian-American actor, I don't often get the opportunity to play the alpha male, this kind of masculine, strong Asian character," he says.

"So I really put the pressure on myself to do the best I can, so other Asian-Americans won't be disappointed by my portrayal of the character."

This is why he will never accept the token Asian role.

"Obviously, getting paid helps. But ultimately, it's about the role and what kind of character I'll get to play. At the back of my mind, I always feel I have a big responsibility to make sure I do a good job not only as an actor for my sake, but also for the rest of the AsianAmerican community," says Lee, who started out as an actor with the East West Players, a prominent Asian-American theatre organisation in Los Angeles.

Before getting his break in The Maze Runner, he was also seen in webisodes made by popular YouTubers and film-making group Wong Fu Productions, as well as in indie films such as the controversial The Stanford Prison Experiment (2015).

Following The Maze Runner, he also snagged a crucial supporting role in television series Unbreakable Kimmy Schmidt, the critically acclaimed comedy created by the 30 Rock team of Tina Fey and Robert Carlock.

In the show, whose second season has just begun shooting, he plays the lovable Vietnamese immigrant Dong, who is also the love interest of leading lady Kimmy (played by Ellie Kemper).

He says: "After The Maze Runner, the doors have opened up a little for me, but it's definitely still a struggle. You don't ever really make it in this business, so you just have to keep working at it.

"I always say we need more Asian-Americans working behind the scenes as well, so that can hopefully raise the status of Asian-Americans in the industry.

"As for me, I'll keep auditioning and reading as many scripts as I can and I'm always going to hustle to find the next great role."

His co-star Brodie-Sangster can certainly understand what it means to persevere in the entertainment industry - he has been acting since he was 11, when he made his debut in the TV movie Station Jim (2001).

The project that made people sit up and notice him, however, is the hit romantic comedy Love Actually (2003), in which he played lovelorn drummer boy Sam.

More than a decade on, people are still talking to him about that role.

"People who recognise me will come and talk to me about my different roles, but that definitely changes a lot around Christmas time," he says with a grin, referring to how the Christmas-themed romcom Love Actually is a perennial movie favourite during Christmas.

"But I'm not sick of it, it's just part of the job. Now people also talk to me about Game Of Thrones and, of course, The Maze Runner," says the actor, who played Jojen Reed in the third and fourth seasons of Game Of Thrones.

For a former child star, he has none of that spoilt-brat vibe or even world-weariness you would expect, coming across instead as humble and down-to-earth. Lee heaps praises on Brodie-Sangster, too, calling him "a genuinely good man" who has "matured despite the potential pitfalls that come with growing up in the business".

It must help that Brodie-Sangster, who is dating actress Isabella Melling, is focused on his craft.

He says: "I used to treat acting as something fun to do and I started to take it as a serious job only when I was 15, as opposed to summer camp. I do roles because I like the idea of playing other characters and exploring other stories, not because of how other people perceive me.

"If people are putting expectations on me because I used to be a child actor, then that kind of thing certainly doesn't come into my consciousness at all. I just enjoy the process of acting and that's good enough for me."