The Tunnel

During a brutal drought, the NSW government reveals a plan to recycle millions of litres of water hidden in abandoned tunnels under Sydney. The plan is abruptly canceled without publicly explained reasons, fueling suspicion. Rumors of missing homeless people sheltering in the tunnels push journalist Natasha to consider a government cover-up.

Natasha convenes with her crew—Peter, Steven, and Tangles—to document what lies inside. After a security guard denies entry, they improvise a second route into the tunnel complex. The setup frames their expedition as a real-time investigation into a potential cover-up.

Inside, they locate the remains of homeless squats and sections once used as WWII air raid shelters. As they press deeper, they stumble upon a vast underground lake that cools the atmosphere with dread. The group feels watched by something unseen in the tunnels.

They find a room housing a World War II air raid bell, a focal point for their footage. Natasha rings the bell to capture its sound on camera, but the loud strike distorts the recording. Tension builds as the space seems to respond to their presence with unsettling quiet.

A malfunctioning boom mic causes tension as Tangles leaves the room to adjust equipment. Moments later, his audio cable is ripped away through a doorway and he vanishes. The remaining crew scrambles to locate him, sensing a malevolent force at work.

The scene pivots to an interview with Natasha, revealing that she is hearing the bell recording for the first time. As the playback plays, screams echo in the audio, implying a violent encounter within the tunnels. This flashback-style cut heightens the sense of dread and raises questions about what happened to Tangles.

Returning to the bell room, the crew discovers their equipment has vanished and a corrugated metal barrier blocks a doorway. They find a room smeared with blood and Tangles' abandoned torch, along with signs that something has moved or stalked them. Reviewing footage, Natasha notices the camera and other gear appear to be repositioned on their own.

A security guard resurfaces and urges them to leave, refusing to help them search for Tangles. As they near a corner, a tall, predatory humanoid drags the guard into the tunnel at incredible speed. Terrified, the trio flees deeper into the labyrinth while the threat closes in.

They hide and switch to night vision, approaching the underground lake where the guard is found with eyes missing. A tall mutant-like creature materializes behind him and twists his neck, then pursues them through the maze, showing a predator that fears light. The chase heightens the danger as the group navigates dead ends.

The group reaches a dead end with a barred opening to a street above and a room showing signs of a living being, plus a small pile of flesh. Their main camera loses power, then briefly comes back as the monster attacks, snapping Natasha's camera lens. She is dragged back toward the lake while Steven and Peter try to fend off the creature.

Natasha uses the night-vision feed to keep watch as Steven and Peter tempt the monster away with light long enough to rescue her. They manage to carry a badly wounded Peter to a well-lit tunnel and call emergency services from a borrowed phone. The trio ends up staying in the tunnel through the night, waiting for help.

In the epilogue, the coroner determines Peter died from extensive internal bleeding. Natasha resigns from journalism, while Steven remains a news cameraman and Tangles' fate remains unknown. Police investigations are closed due to contradictory evidence, leaving many questions unresolved.

Throughout the film, interviews with Natasha and Steven are intercut to frame the events as a documentary investigation. These post-event inserts ground the footage in survivor perspectives and memory. The combination of real-time footage and reflective interviews blurs truth and perception, leaving the audience with an uneasy sense of what really happened.