The official Shadow of the Colossus guidebook includes an explanation of the game’s ending, concept art, an interview with the developers, and unused Colossi. The synopsis below sheds light on the untold aspects of SotC’s story, but be sure to check out the other features as well! Click the images to enlarge.

A heavy price is wrought upon those who undertake the forbidden.
When you gaze into the abyss, the abyss gazes also into you.
A single, pure thought spans the farthest reaches of the earth.

Story – Part 1

A Young Man Steps Into a Forbidden Land

Wander and Agro turn towards the ancient land, an unfailing thought held within their hearts. This is the stage upon which all the cutscenes up until the ending will be unveiled.

A Mask Tells the Legend of an Abominable Land

“That land… began from the resonance of intersecting points… All was replaced by existence and nothingness. Memories scorched into stone, blood and young grass and sky… And a being with the ability to manipulate statues woven of light… In that world, it is said that if one should wish it, one can bring back the souls of the dead… …But to set foot upon that land is strictly forbidden.”

Days pass as Wander continues his trek, traversing moonlight forests and rainy fields. At last he arrives at the ancient land, where time has come to a halt. Crossing a long and intricate bridge, he leaves the girl at the altar of a shrine lined with idols. Black shadows burst forth. With one wave of his sword, the sinister creatures are cleansed, and a voice resounds throughout the chamber. The words blend with the light spilling down from the heavens. The speaker known as Dormin treats calmly with Wander. A petition and a price. For his wish to be granted, he must give something in return.

Story – Part 2

The Forbidden Price That Cannot Be Denied

Penetrated by the jet black bands that burst forth from the bodies of the Colossi, Wander loses consciousness and is swallowed by darkness. Wounds and desperation are further engraved upon his body each time he fulfills part of his oath.

Absent of Good & Evil, Absent of Hatred, the Battles Continue

The black shadows that surround Wander grow more numerous with the defeat of each Colossus. His thoughts are simple and direct. Gazing at the form of the girl, Wander’s strength is restored. Wander’s beloved horse worries for its master. Wander’s thoughts. The girl’s thoughts. Agro’s thoughts… The price is being paid. Each time Wander fulfills his oath, his garb falls further into disrepair and the wounds on his body are etched ever deeper. Wander touches the girl. Her voice cries out to stop him. The thoughts of those who desire and those who do not blend together. The scissors that cut the thread of hope. The consuls who uphold the ways of the world. These are the trespassers that appear in the ancient lands. The intruders follow Wander. Their leader is Emon. Dormin hates the man. A separation from a dear friend strikes at the heart of Wander, pushing onward to achieve his goal…

Story – Part 3

The Being That Was Cursed Awakens

The telling of a tragic story. A welcome demise. The ending connects to the beginning. For the youth, his form drastically changed, and the girl who has awakened, time begins to flow once more.

Destined to Wait For Wander

Crumbled idols. The prone corpse of a girl. Emon bears witness to a dreadful scene. The situation is at its worst. His gaze is met by Wander, who has broken the laws and extended his hand to the forbidden arts. His eyes have lost their light. Two dark horns now grow from his brow. Emon admonishes his foolishness. A white blade pierces Wander’s chest. Morality stands in his way. The darkness has been revived. The forbidden price has been paid. He bids a goodbye to his humanity. Using his body as a catalyst, the being that was once sealed within this world has awoken. Dormin has been resurrected. A thought of the girl is all that remains to oppose the cursed being. This fleeting thought, wistful and sad, envelops the ancient land…

The Young Man’s Pure Thought & the Flow of Time’s Renewal

The ancient sword is cast into the spring. Wander, pulled into the water, is cleansed of Dormin by a sacred power. The giant span of the arch bridge crumbles. The girl awakens in stillness. Wander’s oath has been fulfilled. Standing, the girl comprehends what has occured. Agro, limping on legs injured in place of its master’s, nuzzles her. The two proceed to the back of the shrine as if drawn there. Clutching the horned infant, the girl sets forth. They visit the garden. Sunbeams stream through the leaves, shining down upon them. Small animals appear to greet the three visitors. As though bathing themselves in the gentle flow of time, kites take to the heavens…

Story – Part 4

The Reality That Cannot Be Altered

Wander has defeated the Colossi. A heavy price has been paid. The black shadow has greatly transformed Wander’s shape. Though it is possible to control all his forms, no matter how hard you try, the future cannot be altered.

Wander Changes Shape

Wander returns to the ancient shrine after defeating the 16th Colossus. Waiting there for him are his pursuers from the village, lead by Emon. Once Wander’s chest is pierced by the blade, Dormin, the shadow being once sealed within these lands, takes possession of his body. However, he is unable to completely overcome Wander, and though the response-time is slow, the player is still able to control him.

Controlling Dormin

By pressing the Square button, you can use your right fist to hit the ground. X allows you to breath blue-white flames. It’s possible to crouch by using R1. However, even if your attacks are dead on the mark, you will be unable to defeat Emon and his men, and no matter what course of action you take the tragic ending cannot be changed.

Controlling the Black Shadow

Wander transforms once more, becoming a black shadow. The center of the spring will begin generating gravity, and doing nothing will result in being pulled into the pool. It’s possible to undertake any action you wish, such as jumping or somersaulting forward, as well as gripping edges or the greenery around the spring. By making low jumps, you can approach the girl to a certain degree, but due to the workings of an unseen power, it isn’t possible to get right up to her. No matter how hard you resist, you will ultimately be pulled into the spring.

Controlling the Baby

You can control the baby once it appears on the screen. However, that doesn’t mean you’ll be able to do whatever you wish. You are only able to use its arms and legs to flop about and shed some tears. You can cry using the Circle, Triangle, Square, X, and R1 buttons. Being able to control the baby points indicates that it is Wander, and while he is unable to carry on a conversation, he is nonetheless capable of communicating his will to the girl through his crying. As he now feels he is safe, he is able to cry as much as he pleases.