Everything started because pollution and climate change pushed sharks to evolve faster than usual. A particular shark named Lilith killed off Sophia’s entire research team — her husband included — leading Sophia (played by Bérénice Bejo) to abandon her work as a marine biologist.
But she got pulled back when Mika (Léa Léviant), part of the ocean conservation group Save Our Seas (SOS), reached out to her with disturbing news: Lilith had found her way into the Seine. Mika’s goal was to return Lilith to the ocean safely.
Sharks in the metro were just the beginningSophia warned that Lilith was far too dangerous and would attack anything in her way. Despite this, circumstances with the river police, under the leadership of Adil (Nassim Lyes), forced Sophia, Mika, and Adil to work together temporarily.
However, Mika’s intense mission to save Lilith led her to hold a sit-in at Lilith’s nesting area in the Paris catacombs — not realising the shark had already laid eggs, and her babies were now having babies of their own.
The reason Lilith could give birth without a mate was because she had started reproducing through parthenogenesis — a process that allowed her to become pregnant without fertilisation. She wasn’t just evolving, she had become the origin of a completely new species.
As much as this development looked like a milestone for nature, it spelled danger for humanity. If Lilith and her young ones weren’t stopped in time, their kind could wipe out people entirely.
Before Sophia and Adil could put a stop to the sit-in, Lilith and her offspring had already gone on a killing spree, including Mika and her colleague Ben (Nagisa Morimoto) from SOS.
During a second attempt to destroy Lilith, Sophia and the team came up with a plan that involved setting a trap during the opening round of the Seine triathlon. They had hoped to act earlier, but the corrupt mayor (Anne Marivin) prioritised the financial interests of the triathlon over public safety.
Because of this, the trap was only triggered when swimmers had already entered the river. Sophia used a heat-sensitive light device to draw in the sharks, while her teammates worked on placing explosives.
When the sharks eventually began gathering, Lilith initially stayed hidden but suddenly appeared and killed explosives expert Poiccard (Stephane Jacquot). Shortly after, another officer, Adama (Ibrahima Ba), was ripped apart by the sharks.
As the dynamite finally went off, Sophia and Adil were sent flying through the catacombs by the blast. But the question remained — had they succeeded in eliminating Lilith?
Was Lilith finally taken out?
That wasn’t the case. Lilith emerged straight from the debris and swam up so close to Sophia that she almost touched her. The oversized shark continued attacking and took out two more officers, Markus (Marvin Dubart) and Caro (Sandra Parfait).
Fortunately, Sophia and Adil made it out alive, and it helped that they had started growing closer to each other. Lilith then shifted her focus to the triathlon participants, dragging a net of buoys behind her fin, which might have looked harmless if she weren’t such a massive threat.
One after the other, she began attacking the athletes in the water. As they tried to scramble to safety, they unintentionally pulled in spectators from the banks, giving Lilith more victims to feast on. It was complete chaos.
Even though the military eventually arrived to take charge, their involvement worsened the situation. When Sophia and Adil swam closer to where the killings were taking place, armed forces began shooting into the river, creating panic everywhere.
Now, if you recall an earlier part of the story, you’d remember that live artillery shells from World War II were still scattered in the Seine — a detail that had real-world backing. Although river police had already recovered many, plenty more were left behind.
As Lilith darted around, avoiding the bullets, one of those dormant explosives went off. This triggered a chain reaction of explosions that destroyed several historical bridges across Paris, resembling a destructive Rube Goldberg machine.
The crowd tried to escape in every direction. Manholes burst open due to water pressure, and Lilith managed to weave through it all without getting hit. Things became frantic throughout Paris.
The water reservoirs that were built to pump clean water into the Seine — the ones the mayor had previously mentioned — ended up getting torn apart by the shockwaves from the blasts. Most of the river’s infrastructure also got damaged.
Without any real warning, massive volumes of water surged in, sweeping away everything and everyone.
Does Sophia die in Under Paris?
That wasn’t her end. Right after the massive flooding stopped, Sophia surfaced, still alive. She dragged an unconscious but breathing Adil towards the top of a nearby metro station, and from there, she took in the destruction that surrounded them.
Does Lilith die in Under Paris?
She did not. As the camera moved outward from where Sophia and Adil were located, Lilith and her growing family could be seen circling them underwater. Paris was now underwater, filled with trash, saltwater, and sharks.
One city’s flood becomes humanity’s final warningDuring the end credits, a map began to show how Lilith and her offspring planned to move through more cities, starting from London, then New York, Bangkok, Venice, Tokyo, and beyond.
What this pointed to was clear: unless humans start caring more for the Earth and all its species, predators like Lilith could end up replacing us completely.
Does Adil die in Under Paris?
Even though Adil had gone through heavy physical strain — swimming through tunnels, going into the Seine, and enduring the flood — he was still alive by the time Sophia got him to safety towards the end of the story.
Will Under Paris get a sequel?
No official follow-up has been confirmed yet. However, director Xavier Gens shared that it hasn’t been ruled out. “At the moment, nothing has been set in motion,” Gens told Variety, “but we could be having conversations about it very soon.
If a second part gets the green light, it would happen in a Paris that’s completely submerged under water.”
Are there sharks in the Seine?
Not at all. Mako sharks — the species Lilith started as — cannot survive without saltwater, and the Seine is a freshwater river. The only reason Lilith was able to adapt to the river was because of her unique ability to mutate quickly to new environments.
This trait developed as a reaction to the environmental challenges brought on by climate change.
