The Chronicles of Narnia: The Silver Chair

The Chronicles of Narnia: The Silver Chair is a hypothetical 2012 high fantasy film based on the fourth book in C. S. Lewis' The Chronicles of Narnia.

Plot
Jill Pole is miserable at her school Experiment House; she has been tormented by bullies and is hiding from them. Her schoolmate Eustace Scrubb, who was once a bully himself but is now fearing that he will soon be targeted by the gang he was once part of, confides in Jill about his Narnian adventures, and that his experiences there have led to the changes in his behaviour. Jill initially thinks that Eustace is lying, but when he promises and asks her to attempt to go to Narnia with him, she agrees. Eustace suggests asking fo Aslasn's help, and as the bullies converge on them, the two blunder through a gate that leads them to Aslan's Country.

There, they encounter a cliff, where Jill shows off by approaching a cliff's edge, and Eustace, trying to pull her back, falls over the edge. Aslan appears and saves Eustace by blowing him to Narnia. He charges Jill with helping Eustace find Prince Rilian of Narnia (the son of King Caspian), who disappeared some years before, and he gives Jill four Signs to guide her and Eustace on their quest. Aslan then blows Jill into Narnia, where Eustace is already waiting, near to a great castle he has never seen before. They watch as an elderly and frail man takes ship and sails from the harbour. They learn, much to Eustace's dismay, that the departing King is actually King Caspian, who has set off to see again the lands of his youth – although many believe he has instead set off to seek Aslan to ask who could be the next King of Narnia after him. Trumpkin the Dwarf, now Lord Regent and very elderly and deaf, provides Jill and Eustace with rooms in Cair Paravel, but on the advice of Glimfeather the Owl they make no mention of their quest. Master Glimfeather summons them to a Parliament of his fellow talking owls. The owls explain that Caspian's son, Prince Rilian, disappeared a decade earlier while searching for the green serpent that had killed his mother, and is under the spell of an enchantress.

Jill and Eustace are flown to the marshes on the northern edge of Narnia where they are partnered with the gloomy but stalwart Marsh-wiggle Puddleglum, who serves as a guide, hunter for food in the wilderness, and down-to-earth voice of reason. They journey towargian-landst-lands north of Narnia after crossing the River Shribble. The first giants they encounter take no notice of them, and the trio continue north.

Hungry and suffering from exposure, they meet the Lady of the Green Kirtle accompanied by a silent knight in black armour. She encourages them to proceed northward to Harfang, the castle of the "Gentle Giants", who she says would be glad to have them at their Autumn Feast. Jill and Eustace, overcome at the thought of comfort and warmth, are eager to go; only Puddleglum argues against the journey to Harfang. After several days' journey, and falling into a mysterious chasm in a driving snowstorm, they arrive at Harfang and are admitted inside.

After a night of rest, the three look out a window of the castle and discover the obvious ruins of a giant city in the valley below, which they had passed through but failed to notice due to the snowstorm. They also see the words "Under Me" engraved on the road, which they recognise as Aslan's third Sign. Discovering from a cookbook in the kitchen that they are the main course for the Autumn Feast, they make a narrow escape from Harfang. Following the Sign, they take shelter in a cave under the ruined city, where they fall down a long dark slope into Underland.

They are found by an army of earthmen, who take them aboard a boat across a Sunless Sea to the city ruled by the Lady of the Green Kirtle. She herself is away, but her protégé, a young man, greets the travellers pleasantly but appears to be insane. He explains that he suffers from nightly psychotic episodes, and during these episodes he must, by the Lady's orders, be bound to a silver chair; for if he is released, he will turn into a deadly green serpent and kill everyone in sight. The three travellers determine to witness the youth in his torment, as they sense it could be the key to their quest.

When the young man is tied to his chair, his "ravings" seem instead to indicate desperation to escape an enchanted captivity. After several threats, the youth finally begs the three to release him in the name of Aslan. Recognizing this as fourth Sign, they hesitantly do so. The young man immediately destroys the silver chair. Free from the enchantment, he thanks them and declares that he is the vanished Prince Rilian, kept underground by the Lady of the Green Kirtle as part of her plot to conquer Narnia.

The Green Lady returns and tries to bewitch them all into forgetting who they are, but the barefoot Puddleglum stamps out the enchantress's magical fire and breaks her spell. The enraged Lady transforms herself into a green serpent, and Rilian kills her with the help of Eustace and Puddleglum, and leads the travellers to escape from Underland, having realised that the Green Lady was indeed the serpent who had killed his mother and then captured and enslaved him. The gnomes, who had also been magically enslaved by the Lady, are now freed by her death and joyfully return to their home even deeper in the earth, a land called Bism. One of them shows Rilian's party a route to the surface before leaving. Rilian returns to Cair Paravel as King Caspian is returning home, and Caspian is reunited with his long-lost son just before dying. Rilian is then declared King of Narnia.

Aslan appears and congratulates Eustace and Jill on achieving their goal, then returns them to the stream in his country where Jill first met him. The body of King Caspian appears in the stream, and Aslan instructs Eustace to drive a thorn into the lion's paw. Eustace obeys, and Aslan's blood flows over the dead King, who is revived and returned to youth. Aslan allows Caspian to accompany Eustace and Jill back to their own world for a brief time, where they drive off the bullies before Caspian returns to Aslan's Country. Experiment House becomes a well-managed school, and Eustace and Jill remain good friends.