Trail of the Screaming Forehead

Two sailors, Big Dan and Dutch, arrive in Longhead Bay and quickly strike up a wary friendship with the local librarian, Millie Healey. They begin to sense something deeply unusual about the townsfolk as foreheads start to claim control. The coastal town's mood shifts from curious to uneasy as the threat starts to creep in.

The trio encounters a crawling forehead and manages to crush it, signaling the parasite's bold presence. They report the incident to the police, only to be met with disbelief and indifference. A pattern begins: the community remains untrusting as more foreheads slip into control.

Dr. Sheila Baxter becomes convinced that true independent thought resides on the forehead, driving her to conduct experiments that blur ethics. She also engages in an affair with her colleague Dr. Philip Latham, further complicating loyalties. The plan to harness foreheads for her own purposes begins to take shape.

Baxter strikes a deal with local hoodlum Nick Vassidine to acquire more foreheads for experiments. Nick's moll, Droxy Chappelle, seduces Big Dan and leads him to a freezer aboard his boat, where medical cadavers are stored and foreheads are harvested. The threat grows more tangible for the town.

Dr. Applethorpe, already under alien influence, invites Philip to a secret gathering where the aliens debate disguises. They eventually settle on headpieces with veils to blend in with humans, signaling a deeper plan to infiltrate society. The atmosphere grows tense as loyalties blur.

Millie, Big Dan, and Dutch delve into the town library to find a reference that could repel or harm the foreheads. They uncover hints about sound-based defenses and other potential countermeasures. The search provides a glimmer of hope amid creeping dread.

A forehead attaches itself to Millie, and she is briefly captured before the trio subdues the creature. The attached forehead confesses its origin: their race hails from a war-ravaged planet and seeks to inhabit human hosts. The revelation underscores the seriousness of the invasion.

The aliens' origin is clarified, and the police are sidelined as Chief Bartnett is revealed to be under alien control. This betrayal triggers a frantic chase through the town as the invaders tighten their grip. The resistance grows as more townsfolk awaken to the threat.

Philip Latham admits his affair and the strain it caused, yet he continues with the experiments in defiance of morality and safety. The personal and professional lines blur as the alien influence deepens his resolve. His inner conflict mirrors the town's moral chaos.

Philip's forehead-possessed state grows into a monstrous transformation, with a bulbous presence terrifying those around him. He flees in panic as the alien control fully asserts itself. The town braces for a final confrontation.

Millie learns through a library clue that certain sound frequencies can harm or repel the foreheads. She and the sailors craft a plan using bells to deter the invaders and buy the town some time. The defense is imperfect, but it offers a crucial window of hope.

The aliens retaliate by introducing earplugs that dull the effect of sound, making the bells less effective. They manage to recapture Millie and her companions, tightening their grip on the town. The resistance scrambles to adapt to this new defense.

In a final act, Philip returns in a damaged, fearsome state and detonates the fire alarm, knocking out the possessed but destroying himself in the process. The town reels from the assault, clinging to the memory of the sacrifice. The immediate threat seems to be contained, but the danger lingers.

An extra forehead crawls into a prop rocket in the aftermath, muttering of revenge and vowing to return. The town's sense of safety remains fragile as the possibility of another invasion lingers just out of sight. The closing beat leaves the ending open and unsettling.