The Bermuda Depths

On a Bermuda beach, Magnus Dens is sleeping when a beautiful, mysterious woman named Jennie Haniver approaches and seems to recognize him. The moment feels dreamlike as Magnus wakes from a memory-laden reverie. Jennie's presence hints at a past connection that will haunt him.

As a child on the same beach, Magnus watches a turtle egg hatch and shares the moment with Jennie. He carves 'J+M' inside a heart on the turtle's shell, and Jennie makes him a cowrie shell necklace. These early acts bind the pair to the sea and to each other.

The scene shifts to their youth as Jennie rides a grown turtle, heading toward the open sea. Magnus watches as she disappears beneath the waves while he calls after her. The memory deepens the mystery surrounding Jennie.

Magnus dreams of the night his father Lionel was knocked into the water by an unseen horror in the cave beneath the house. A storm rages as part of the cliff-side house crumbles toward the beach. The nightmare foreshadows the danger and the sea's hold on him.

Magnus wakes, meets his childhood friend Eric at the docks, and is introduced to Dr. Paulis, who is studying teratology. That evening, Eric and Doshan join them for dinner at Paulis' house, and Magnus is intrigued by Delia's necklace, which resembles his own.

During the boat trip, the craft lists violently as a figure of enormous strength tears the net from the line. The crew senses a heavy underwater presence, casting a pall of danger over the voyage. Magnus and Eric brace for whatever lurks beneath the water.

After dinner, Magnus steps outside and encounters Jennie again; she is a living manifestation of his memory and he learns her name directly. Dr. Paulis dismisses his account as folklore, suggesting 'Jennie Haniver' is a local sea creature in legend. Delia later explains the true myth: a vain woman who bargains with a god to survive a storm and becomes a sea creature forever on land no more.

The next morning the police bring Eric in to examine large tracks on the beach, hinting at something unnatural. Magnus goes to the shore and meets Jennie, recognizing her as his childhood friend. He leads her to his father's wrecked house and recalls past memories as she recounts the quadrilles her father held in their great hall.

Magnus confronts Paulis about his father's death. Paulis explains Lionel was conducting mutation tests on sea life and was attacked and eaten. Magnus asks whether the turtle from his childhood ever mattered, and Paulis expresses dismay at the memory. This deepens the tragedy and the connection between science and the sea.

Eric wants to unleash the Horror, a harpoon-firing device, to capture or kill the sea threat. After some tension, they head back out, and Magnus reveals his earlier night with Jennie. They encounter the sea's power as the turtle tears through the net and the crew continues to trawl, with Eric firing at the unknown form.

After sundown, the boat's power fails and the compass spins; Jennie appears on deck begging Magnus to free the turtle, hinting at a long-ago promise she regrets. Magnus is drawn to her, while Eric remains skeptical and focused on the hunt. The sea seems to reply in green-lit glances from Jennie's eyes.

Doshan arranges Dr. Paulis' rescue by helicopter, which spies a huge shape underwater. The turtle surfaces, leaps toward the helicopter, and crashes it into the sea. Magnus tries to help Eric aboard but is tangled in the Horror's line as Jennie's eyes glow green and the giant creature drags Eric under.

Jennie approaches an unconscious Magnus on the beach, kisses him sadly, and returns to the depths for the last time. The sea's hold on Magnus deepens as he grapples with loss and memory, now sealed with Jennie's departure.

Doshan confronts Magnus at the graveyard where his parents lie, expressing horror at the losses of her husband and Dr. Paulis. Magnus tells her he is leaving Bermuda and wants nothing to do with the sea ever again. He walks away, unaware of the Jennie statue and its inscription nearby.

On the ferry leaving Bermuda, Magnus removes the necklace Jennie had given him and sadly throws it into the sea. It sinks past the giant turtle, which is shown to have the same initials Magnus inscribed on its shell all those years ago. The film closes on memory, loss, and the sea's enduring hold over Magnus.