Cold Open

On a foggy London night, a policeman makes his rounds, passing I.M. Foreman’s junkyard at 76 Totter’s Lane. As the policeman passes by onto the remainder of his round, the camera pans across the mist-shrouded junkyard. In its corner stands an incongruous-looking police box emitting an eerie hum, lit from underneath by a mysterious floating casket…

(Nice try, Midjourney – though the windows are a bit wrong…)

Act One

Orientation/Exposition

Another day of classes ends at the Coal Hill School. History teacher Barbara Wright and science teacher Ian Chesterton compare notes on an enigmatic student, Susan Foreman. Her knowledge of history and science surpasses the rest of the class and possibly the teachers. However, she has very curious gaps about present-day culture — for example, she forgets that England has yet to adopt a decimal currency. Barbara has encouraged her to specialise in history, but Susan is resistant to her suggestion about in-home tutoring, saying her grandfather, with whom she lives, doesn’t like strangers. Barbara tells Ian she got Susan’s address, 76 Totter’s Lane, from the school secretary. She went there and found, not a house, but a junkyard. 

Turning point

They find Susan so Barbara can lend her a book on the French Revolution. Ian offers Susan a ride, but she declines. Ian and Barbara resolve to follow her home. After they leave the room, Susan absent-mindedly splashes pen ink on a piece of drawing paper that she then folds to smear into abstract patterns, strangely reminiscent of the opening sequence of Doctor Who. She picks up a pencil and sketches six lines into a rough hexagon before she snaps out of her reverie. Apparently terrified at what she has drawn, she looks up in alarm to check whether she has been observed before surreptitiously turning on a Bunsen burner to set fire to the piece of paper before letting it flame and flutter out in the dry well of the sink of a science room desk, the ashes consuming any evidence of her sketch before flushing spirally down the drain, which the camera follows, again evoking the opening credit sequence of the programme.

Act Two

Rising action

Arriving by car at 76 Totter’s Lane, Ian and Barbara see Susan enter the junkyard alone. Following from a distance, they search the junkyard for her in vain.

Ian is transfixed by a police box there which hums. The observant viewer will notice that the glowing, floating casket is gone. Touching the police box, Ian exclaims that it’s alive. They hear someone coming and hide. An old man approaches the police box and unlocks it. 

Second turning point 

The teachers seem to hear Susan’s voice from inside, greeting him. They confront the old man, who brusquely shuts the door and refuses to acknowledge that anyone is inside. When they threaten to go to the police, the old man calmly dismisses their claims. 

The door opens from the inside. Hearing Susan’s voice again, the teachers push past the man. They are astounded to find themselves in a much larger space, with futuristic electronic panels and a central hexagonal control console.

Act Three

Crisis point 

The interior of the TARDIS is unveiled for the first time. Susan is shocked to find her teachers there. The old man, her grandfather, is furious at their untimely intrusion.

Susan and her grandfather, who calls himself simply the Doctor, say the police box is actually a disguise for their space-time ship, the TARDIS. They are alien refugees from another planet and time. 

Climax

Despite Susan’s protests, the Doctor prepares the TARDIS for take-off, saying he must kidnap Ian and Barbara to protect Susan and himself. The sudden take-off renders the two school teachers unconscious. 

Coda

The TARDIS arrives on a desolate landscape, over which then falls the shadow of an unknown figure.

Acknowledgement: Synopsis adapted from https://tardis.fandom.com/wiki/An_Unearthly_Child_(TV_story)