Watch Matthew McConaughey & Anne Hathaway Explain Their Full-Proof Seasickness Cure

Matthew McConaughey and Anne Hathaway’s upcoming neo-noir thriller Serenity, out Jan. 25, tells the chilling tale of a gorgeous island that harbors many secrets. In the film, McConaughey plays a fishing boat captain who moves to Plymouth Island following his divorce, starting a new life and even changing his name. But his new life is disrupted when his ex-wife, Karen (Hathaway), finds him and asks for him to kill her abusive husband.

Serenity was filmed in Mauritius, per Variety, an island in the Indian Ocean off the southeast coast of Africa. And, in the film, it looks like the ultimate paradise. But during the flick’s Los Angeles press junket, the cast and director revealed to Bustle writer Sydney Bucksbaum that filming wasn’t all smooth sailing.

One of the big issues about filming in an island is that weather isn’t always great. And that includes lots of rain, which was McConaughey’s least favorite thing. “For me would be when the heavy rain would come and everybody — 20 people would be down in a cabin,” says the actor. “It wasn't that big of a cabin,” adds Hathaway, laughing.

And filming on a boat had some other downsides, too. For Hathaway, the biggest challenge was delivering her lines over and over again, because the sound wouldn’t be right. “Sound is a little tough to film on a boat," explains the actor. “It'd be frustrating to be like 'Oh I really liked that performance!' And they're like yeaah, but nobody can hear it.' And I'd go, 'Okay, here we go again'.”

And when you’re filming all day on a boat, chances are you’ll feel a bit queasy at some point. But the cast handled it like pros. McConaughey, who admits he’s definitely been seasick before, says he found the best solution to seasickness, and it’s both genius and so yummy — but you’ll have to watch the clip to find out what it is.

Luckily, the director, Steven Knight, assures that nobody had any accidents on set that made them fall into the water, which would've been a huge hassle while filming. But he does mention that something pretty scary happened while filming a scene with McConaughey.

That doesn’t mean the cast didn’t have any opportunities to take a dip in the ocean, though. In fact, that's how they celebrated the end of the shoot. “We’d been filming this sequence on a dock and it was just so hot […] and on the last day, we told ourselves we were going to record ourselves jumping in the water,” remembers Hathaway.

Despite some challenges, it’s clear the cast had a blast filming the thriller. This week, Hathaway shared an Instagram post with a lengthy caption, discussing how much making Serenity meant to her. "I find Serenity to be a thrilling, ambitious, violent, spiritual, erotic, charged, dark, damning, contradictory, maddening, lushly intelligent film from the brilliant mind of Steven Knight," wrote Hathaway.

The trailer hints that there are tons of mysteries that haunt the island, making Baker question the intentions of people around him, while also grappling with his decision to help Karen. And it sounds like the gorgeous locale — with all its filming snags — perfectly fits the film's idea of paradise being an illusion.