Fate cannot be changed or can it?
The Dahaka - the Guardian of the Timeline - seeks the Prince for he was meant to die as a consequence of opening the Hourglass despite having rewound back to before he did in the Sands of Time.
The Old Man directs him to the Island of Time where both the Hourglass and the Dagger of Time originated before passing into the possession of Farah's father - the Maharajah.
His vessel is intercepted and the hired crew is slain by the underlings of a woman called Shahdee who is the bodyguard of a kind for the Empress of Time.
Her mark on the Prince is to give him the scar he will bear on his face for the rest of the game. She also shows him how he can travel backwards and forward through time on the island. Something that infuriates her mistress - the Empress.
The Prince inevitably slays Shahdee and gains the assistance of another called Kaileena. Indeed the Prince's antagonists are many in both the past and the present. In the present you will face what remains of the Palace's defenders and the Dahaka who has managed to follow you to the island.
It is usually only in the present that you will be running from him only to discover its vulnerability to water.
In the past, your efforts will be directed towards 'gaining' an audience with the Empress only to learn she was always a lot closer than you knew, but perhaps you suspected her identity early on.
Instead of visions of the future, you rely entirely on your own strategies as you alternate between past and present on the island. The two versions of the Palace start to overlap as things once totally broken in the present are suddenly not so broken after all while things you do in the past alter the ruins in the present.
You will learn that it is you who are responsible for the creation of the Sands of Time as your attempt to destroy them instead creates them.
However something found in the present shows how you can accomplish the impossible - a time line once changed can be changed again - but the question remains can fate be changed as well?
Only by traveling through time can that be answered.