The former Six Flags theme park in Louisiana, which was closed after the damage and flooding wreaked by Hurricane Katrina, is alight for the first time since that devastating event. In the years that followed, it had become part of the surrounding swamp, and home to alligators, armadillos, snakes and the other flora and fauna of this part of the world. It was about as far from habitable as could be.

But the crew of PERCY JACKSON: SEA OF MONSTERS have moved in for a two-week shoot at the park, which will double for the damaged lair of the blind cyclops Polythemus as part of a new quest for the character first brought to the big screen in 2010’s PERCY JACKSON AND THE OLYMPIANS: THE LIGHTNING THIEF, which grossed more than $200M at the global box office. The crew has spent the past five weeks getting it ready: laying down new wiring and adding to the rundown nature of the place. Oh, and moving the alligators out.

“It’s a pretty eerie set and a pretty harsh environment to work in,” says Logan Lerman, who returns to the title role. “Hot, humid and full of bugs.”

“They took out all the alligators that had been there, but there are still armadillos other creatures walking around,” laughs Alexandra Daddario, who returns to the role of Annabeth. “So you’re sitting there in the mud, tied up to posts, with bugs crawling all over you: all you can do is laugh. It’s either laugh or cry, and it’s best to laugh!”

Still, if it seems like the cast and crew are enduring hardships to bring this story to the screen, their quest is nothing to that of their heroically inclined fictional counterparts, and it’s born of a keen desire to return to the Olympian world of PERCY JACKSON. “There was definitely a period of time when we wondered: will that be it?” remembers Lerman. “It was fantastic when this movie came together, and it was nice to have that period of time away.  It’s great to come back into the old shoes and play Percy again.”

Indeed, all of the returning cast are enthused to return, as much to see each other as to follow Percy’s adventures. “I’ve become so close to these people,” says Daddario. “Logan and Brandon Jackson, I’m so close with them that it’s like going to do a film with your best friends. It’s a level of familiarity which means you feel really comfortable.”

But while the characters are the same, the journey they’re on is different. In PERCY JACKSON: SEA OF MONSTERS, the safety of the demigods’ home at Camp Half-Blood is threatened when the perimeter defences are destroyed. Percy, Annabeth and their satyr protector Grover (played by a returning Brandon T. Jackson) must quest to find the Golden Fleece, which is in the care of the violent blind cyclops Polythemus, so that they can bring life back to Thalia’s Tree, the mystical oak that keeps their home safe.

“At the end of the first film Percy was the hero,” explains Lerman of his character’s journey. “But at the start of this one, he’s been replaced by Clarisse, the stronger, better demigod at Camp Half-Blood. He feels insecure, he’s full of self-doubt, and he’s constantly being beaten by Clarisse.”

Played by Leven Rambin, a newcomer to the series, Clarisse is the half-blood daughter of Ares, the god of war. And she’s fixing for battle at every opportunity. “She’s a bully,” says Lerman. “She’s very competitive, very tough and she stomps on Percy at every opportunity.”

But if Percy is feeling the heat, at least he still has the support of his friends. Fans of the books will be especially pleased to learn that Annabeth dons blonde locks in the films for the first time in SEA OF MONSTERS, just like her character in the books. “I think the character is more in touch with the books too,” argues Daddario. “This is a very difficult and emotional journey for her, more so than in the first film, because she’s questing to save a character who’s very close to her.”

Daddario won’t be drawn on just who it is she’s questing to save, but fans of Greek myth will know that satyrs and quests for the Golden Fleece don’t mix. “We’re all older and a little wiser,” reveals Jackson. “And my character really doesn’t want to go on this quest. He knows that cyclops eat satyrs for breakfast. This one’s a death wish for him.”

It doesn’t help that a cyclops turns up at Camp Half-Blood before Percy and co. even get a chance to set off. Tyson, played by series newcomer Douglas Smith, turns out to be Percy’s half-brother, the product of Poseidon’s dalliance with a nymph. “Cyclopes have a reputation for being monsters,” explains director Thor Freudenthal. “So his arrival is bad news for a lot of the half-bloods, including Percy.”

“Brotherhood and the importance of family is definitely a new theme for the series,” continues Lerman, whose character is jealous of the apparently close relationship Tyson has with Poseidon, who doesn’t appear to communicate with Percy at all. “We had a great time playing it: Douglas was a blast and was a great addition to the cast.”

Tyson accompanies the trio on their quest this time, much to the chagrin of Annabeth. “If you’ve read the books, you’ll know she has a solid reason for disliking Cyclopes,” reveals Daddario. “And so part of the journey of the film is all of them learning to accept Tyson. Is he a good guy or a bad guy? Will he mess everything up or help save the day?”

Indeed, she says, it’s part of the charm of the PERCY JACKSON films that these high-concept themes still offer relatable themes to audiences of all ages. “Always in life you’ll meet people you’re not sure of and maybe you’ll take against them for the wrong reasons, so it’s relatable in that way.”

Continues Freudenthal: “Tyson comes in with the best of intentions and with incredibly strong will and excitement. So as much as he mixes things up within the group, in the end he really helps Percy become the hero he needs to become.”

Freudenthal himself is mixing things up. He comes to PERCY JACKSON: SEA OF MONSTERS fresh to the franchise – Chris Columbus directed the first film – and brings a new sensibility to Rick Riordan’s popular world. “He’s completely different from Chris,” says Lerman. “Tonally, the movies are very different because of the different filmmakers. I think this is definitely lighter than the first one. It’s more comedic, and more fun. I loved that about his vision.”

Many directors would feel intimidated following in the footsteps of Columbus, who is a veteran of films like HARRY POTTER AND THE PHILOSOPHER’S STONE, MRS. DOUBTFIRE and HOME ALONE. But Freudenthal was grateful for the work Columbus had done to establish the universe of PERCY JACKSON. “I was able to build on what Chris had done and go from there. I could have fun with the world and maybe refine the tone for myself. I have a very different visual style than Chris, which I can’t even necessarily pinpoint. The first movie does the job of establishing things for you, so your job is to dive in deeper, broaden the range, expand the world and have fun with the relationships and the characters.”

Freudenthal was also keen to bring in more of the book than the screen time of the first film allowed. “I wanted to expand the grand mythology of it, having to do with the character of Thalia and the tree that she becomes,” he explains. “What I really liked about the books is that they have their first person narrative as if written by Percy. So there’s a sort of lightness to that, a bit of irreverent humor and style that is firmly in place in this movie.”

And while THE LIGHTNING THIEF introduces the Olympian Gods, this film deals more in the fauna of their world, and all its various beasties. “Scale-wise this is a much bigger movie,” enthuses Lerman. “There are so many more creatures and visual effects. It’s huge.”

Agrees Daddario: “The monsters definitely get bigger! We go to the Sea of Monsters and something pretty unbelievable happens there. We really take the cliffhanger moments to a different level this time around.”

Freudenthal is enthusiastic about this kind of quest moviemaking. Every day, he says, there’s a new challenge and a new “mini-movie” to shoot. “It’s a dream because I felt like, within our four months of shooting, we were dealing with so many different methods of making a movie in so many different places, whether it’s digital, practical, location shooting and the rest. It keeps you on your toes, I’ll say that.”

Keeping the entire cast on their toes was the inclusion this time around of veterans Stanley Tucci and Nathan Fillion to the ensemble. “That’s the great thing about these movies is you’re there the whole time and all these great actors come in,” says Daddario. “The people I get to work with and learn from are unbelievable.”

Working with Tucci was a master-class for Jackson, a stand-up-turned-actor who admired his co-star’s comic chops. “He had this off-kilter approach to the character, which takes a certain talent,” he remembers. “He gave Dionysus this, ‘don’t want to be here,’ swagger, which is great for the show because everyone knows a camp counsellor never wants to be there but he’s doing it for the check or is burdened by the kids. So he’s like, ‘Go do a quest, I’ll be over here.’”

Of course, for a film defined by clashes with monsters, there are plenty of scrapes for the cast to get themselves into this time. Freudenthal was amazed at how much Lerman, Daddario and Jackson knew about stunts, fighting and wire work. “They were so much more experienced with all that stuff than I was,” he laughs. “But this movie presented different physical challenges for them in that we didn’t want to repeat the action of the first film. Based on their old experiences they were ready to take things to the next level.”

Lerman remembers three months of fight training on the first PERCY JACKSON film, so was grateful all of that knowledge was inherent to begin with, and the time didn’t need repeating for SEA OF MONSTERS. “It was insane,” he says. “It was our first time doing anything like this so we really had to figure it out. I’d never held a sword before. But now we kind of know what we’re doing and it was much, much easier to jump back into it.”

Lerman says that after two movies playing Percy he knows his way around a sword. So is he a dangerous man to be around? “I think so,” he laughs. “But then, I think anyone would probably be. I think it’s pretty easy. You just chop.”

So after two PERCY JACKSON movies, Lerman certainly knows his way around a sword. And if anything’s certain about their quest this time out, it’s that combat will play a big part. As with everything in Percy’s world, only the most courageous need apply.