Long establishing shots of the sea, accompanied by Moog and flute music. Seagulls circle overhead. Sarah begins a rambling voiceover about unspeakable ancient horrors lurking beneath. The camera slowly pans across a deserted beach. Five minutes in and still nothing has happened. A figure appears in the distance and runs towards the camera. There is no jump cut. As the figure gets closer, we can see that she is a woman in a catsuit. Still no jump cut. As she gets closer, we can see that she isn’t wearing a bra. And still no jump cut. Her face eventually comes into shot. It’s Gemma. She runs up to Sarah, who is splashing around in the sea. They see a figure in the distance. It eventually turns out to be Slater (Glyn Owen). When he sees Sarah and Gemma, he hides behind the sea wall. Meanwhile, on another part of the beach, Old Evans (a comedy Welshman played, inevitably, by Talfryn Thomas) reacts to an unseen menace. Sarah and Gemma have a vague conversation about sea monsters, shot entirely from behind Gemma with no cuts. Suddenly (at last, a fast cut) a monster appears. It is blatantly copied from Rover in the Prisoner. Gemma runs away but falls over for no reason and twists her ankle. As she lies on the beach, the monster keeps coming and coming as the director desperately tries to get the episode up to length.
Soldiers arrive and shoot at the monster until it returns to the sea and disappers. Slater watches from behind the sea wall and then sneaks away. Captain Hunt (former 60s pop star Steve Ledge) questions Sarah and Gemma. He asks if the monsters are aliens, but Sarah says they are called Cretaceans and have lived on Earth since before humans. Hunt is perplexed, but agrees that they are very dangerous. Sarah says the Cretaceans could have a human ally on shore.
The camera slowly pans across a hill above the town. It comes to rest on Slater operating a radio. The camera pans again and zooms towards the sea, accompanied by morse code sound effects. Cut to a Cretacean floating in the sea. The camera stays on it too long while nothing much happens.
Meanwhile, Sarah and Gemma spend some time sitting by Whitstable harbour, watching the boats coming in and going out again. Old Evans wanders along the quay. Sarah asks Evans about the monsters and he mutters something about unspeakable horrors. Gemma demands to know if he is helping them, but he denies it and says they should keep an eye on Slater, before nervously walking away.
The soldiers detect some transmissions and trace the source. As they surround Slater’s house, Gemma grabs a Sterling sub-machine gun and bursts in through the front door. Close-up on Slater holding a pistol. He fires.