Cut off from the mainland after a devastating shockwave, a secretive government agent must guide a fractured Scottish island community, as an unseen presence begins to influence who stays, and who leaves.

SYNOPSIS:

Callum Macrae, a government technician with a concealed mandate, is sent to a remote Scottish island to reactivate a long-abandoned Cold War bunker. The island is already uneasy, cut off by a dense unnatural fog, with the sea and sea life behaving strangely and the community quietly fraying under the surface.

Among the islanders is Sara, a marine researcher and Callum’s former partner, now fiercely protective of her son Ben. Their reunion is strained, shaped by unresolved history and a shared instinct that something is wrong. Increasingly treated with suspicion by the locals, Callum begins quietly to restore the bunker’s systems, intercepting fragmented transmissions from the mainland. Warnings that cut out mid-sentence, replaced by strange distortions and something far more disturbing.

When a fishing boat is lost in an horrific electrical fire just offshore, the island is shaken. A funeral is arranged, but before the community can grieve, a violent shockwave strikes from the sea, devastating the coastline and leaving many dead or injured. Communication with the mainland then collapses completely.

In the aftermath, as the islanders try to recover, a Royal Navy destroyer appears on the horizon, silent and unresponsive. As fear mounts, a group of islanders, led by the local priest Graham (now Sara's partner), attempt to reach the ship, believing it to be their only hope. Callum tries to warn them off, but too many cannot hear him. The ship responds with lethal force, destroying the boats and killing Graham, deepening the island’s isolation and mistrust of Callum.

With the community fractured, the survivors turn on Callum, convinced he is hiding the truth. Retreating to the bunker, he makes further contact attempts, first through local radio, then via a satellite link, only to receive horrifying transmissions: fragments of human voices, distorted beyond recognition, layered with what sounds like screams. Alarmed, Callum sets about trying to decipher them, as Ben watches secretly.

Meanwhile, the grieving Sara continues her investigations in the water, where she encounters a powerful, unnatural signal emanating from the depths, something that seems to affect both the environment and the people, even her son. Those who consume fish from the sea or linger too long near the shoreline begin to change: withdrawn, unresponsive, their behaviour subtly altered.

As more islanders succumb, Callum begins to understand that whatever has disrupted the mainland is not contained, and that the Navy ship is not there to rescue them, but to keep them isolated.

When a damaged nuclear submarine drifts ashore, its crew dead or unhinged, the truth becomes clearer: something has been awakened, and it is communicating, not through machines, but through people.

As the island deteriorates, Ben too begins to exhibit signs of influence. In a desperate moment, he attempts to walk into the sea, drawn by something he cannot resist. Callum and Sarah manage to pull him back, and in doing so, Sara finally reveals the truth: Ben is Callum's son.

As they lie on the shoreline with the catatonic Ben between them, the fog lifts just enough to reveal a haunting sight.

A vast flotilla of boats, small and large, is approaching the island.

Back in Callum's bunker, one final transmission comes in. A message, simple and absolute:

“MESSAGE RECEIVED.”