This summer belongs to aquatic horror, and the reigning king of aquatic horror – the shark- is ready to take a bite out of the box office with 47 Meters Down: Uncaged. Swimming into theaters on August 15, Uncaged follows four divers who find themselves in a world of trouble when they enter the territory of the deadliest species of sharks while exploring a submerged cave system. If the trailer is any indication, director/co-writer Johannes Roberts is upping the shark-induced terror in a major way over his 2017 sleeper hit 47 Meters Down. To prepare for its release, we look back at Roberts’ unnerving shark horror film that started it all, and its unique journey to box office domination.

In the summer of 2017, an indie thriller featuring a pair of sisters trapped in a shark cage 47 meters below the ocean’s surface quietly released into theaters. Just like the silent apex predators featured within, that shark thriller took a major bite out of the box office and caught everyone by surprise. 47 Meters Down became one of the biggest sleeper hits of the year, and its sequel is poised to attack the box office very soon. Yet the road from production to release was long and twisting; if not for an eleventh-hour rescue, the reception of this film would’ve been dramatically different.

Directed and co-written by Johannes Roberts (The Strangers: Prey at Night), 47 Meters Down was a small budget affair shot mostly in a water tank in Basildon in the UK. Exteriors and the gorgeous clear waters were filmed in the Dominican Republic. The small cast revolved around Mandy Moore, just before her turn in the Emmy-winning series This Is Us that would catapult her back in the spotlight, and The Vampire Diaries’ Claire Holt as the ill-fated sisters Lisa and Kate. Matthew Modine (Stranger Things, Full Metal Jacket) appeared in much smaller capacity as the captain of the shark-diving boat.

At the script stage, Bob Weinstein’s Dimension Films picked up U.S. distribution rights to the film. But their deal never included any details or requirements for theatrical release. Thus, August 2, 2016, was set for home release. But a string of underperforming films and a failed TV sale for Dimension meant not as much money to support the home release. Even when a positive test screening indicated the film could do well in theaters. In an even more curious move, Dimension Films retitled the film In the Deep, a title that had once belonged to 2016’s The Shallows. As the release date loomed near, DVD review copies were sent out under this title.

Everything changed when a new distributor entered the picture, one that believed in the theatrical release capabilities of the product. Entertainment Studios entered weeks of discussions and negotiations with Dimension, finally closing a deal on the very day In the Deep hit shelves. The DVDs were pulled from shelves, the release canceled, and the title reverted back to 47 Meters Down. Entertainment Studios was committed to a theatrical release, which meant waiting until June of 2017.

It was a gambit that paid off in a big way. By the time the film did see release, Mandy Moore had become a bigger sell thanks to This Is Us and The Shallows proved sharks could be a huge draw in theaters. The $5-6 million-dollar feature opened to $12 million the weekend of June 16, 2017. Not huge, but not too shabby at all for the low budget film. But then, the following week it rose up the ranks. Any drops were surprisingly minimal. Cut to a month later, and 47 Meters Down amassed $42 million in domestic gross. It’d become a sleeper hit, and one of the highest grossing indie films of the year.

A tale of two women fighting for survival against sharks and narcosis at the depths of 47 meters took a simple concept and turned it into around 90-minutes of thrills and chills, including one of the biggest jump scares in recent years. It’s fitting that the behind the scenes trajectory of turning this little indie into a sleeper hit is just as full of adventure. Now, Roberts has returned to unleash the sequel, presenting an even more terrifying scenario that sees four women unwittingly entering into the territory of deadly sharks when diving in a claustrophobic labyrinth of submerged caves.

47 Meters Down: Uncaged arrives in theaters on August 16, 2019.