Aquarium of the Dead (2021)

At the Shining Sea Aquarium, Dr. Karen James and two workers attempt to tag the resident octopus. The octopus goes into cardiac arrest as the result of the procedure and seemingly dies, then reanimates, attacks Karen, kills the two workers, and escapes into the ducts.

Meanwhile, aquarium scientist Miranda Riley receives a transmission from the Eden Wildlife Zoo warning her to dispose of any epinephrine the aquarium received. Her colleague Daniel Hanley assures her that he took care of the disposal before leaving to guide Skylar, a tourist, on a V.I.P. visit to the aquarium. Miranda meets with Senator Bailey Blackburn, who is responsible for securing additional funds for the facility, but they are interrupted by Karen warning them of the octopus. They alert security chief Eddie "Clu" Cluwirth of the breach.

Before the staff can take any action, contaminated slime left by the octopus infects the rest of the animals in the aquarium, who shatter their tanks to escape. Miranda, Karen, Blackburn, and Blackburn's aide Beth take shelter in a theater as the aquarium goes into lockdown. Elsewhere, Daniel and Skylar attempt to get back inside the building. They are attacked by a group of zombified spider crabs, but escape and manage to get inside.

Miranda's group ventures out of the theater, surmising that if they can reset the aquarium's power, the lockdown will be lifted. They come across Daniel and Skylar, as well as zombified crocodiles and walruses. Skylar loses his composure, attacks a walrus, and is killed by it. As a result of the encounter, Karen realizes the reanimated animals are blind and navigate based on sound. This allows her to use her mobile phone to trick the walrus and lead it away. However, the group soon discovers an undead starfish stuck to Beth's abdomen, which had slipped unnoticed into her notebook earlier. They cannot detach the starfish and Beth soon dies from it feeding on her.

The group passes through a shark habitat, then unites with Clu and ventures into the basement, where they are confronted by the octopus. Clu sacrifices herself in a failed attempt to kill the octopus while Miranda resets the power. Cornered by the octopus, Miranda uses a stray power cable to fatally electrocute it. The reset lifts the lockdown, and the group escapes. As they leave, the truth about the incident is discovered: Daniel was conspiring with Blackburn to cut costs at the aquarium and did not dispose of the epinephrine from the Eden Wildlife Zoo as he said he did, leading it to be used on the octopus and cause the outbreak. Miranda punches Daniel, breaking his nose, and leaves with Karen.