Uprising 's story begins after the events of
Halo 2, in which the alien collective known as the
Covenant discovers the location of Earth and begins a full-scale invasion of their enemy's homeworld.
The supersoldier Master Chief is stowed away aboard an ancient Forerunner ship. On a course set for Earth, he is overwhelmed by a Covenant strike force and rendered unconscious. In the next scene, Colonel
James Ackerson is being tortured by Covenant forces on Mars, to whom he betrays the existence of something called "The Key of Osanalan." Ackerson admits the Key is located in
Cleveland, Ohio. In Cleveland, the narrative follows the point of view of a hotel concierge named Ruwan as the city falls under attack by Covenant forces. In the mayhem he meets a woman named Myras Tyla. Tyla remains calm even as Ruwan edges towards all-out panic. The pair are captured and with other residents herded into a sports stadium. The Covenant declare that the humans must give up the location of the Key to save their lives; Tyla is confused, but Ruwan states he knows exactly what it is.
Onboard the Forerunner ship, the Master Chief is captured and interrogated by Covenant forces, but manages to escape using a concealed weapon. On Earth, Ruwan and Tyla escape detection by the Covenant and appropriate a vehicle in an effort to escape. Ruwan reveals that the Key is in fact a fictional object that he and his brother James Ackerson made up as children; James told the Covenant about the Key in order to prevent the outright destruction of Cleveland. After fighting Covenant forces, Ruwan and Tyla are rescued by marines and leave the city.
The Master Chief attempts to kill the Covenant's leader, Prophet of Truth, but is discovered as he takes aim; Truth escapes as the Chief is left to kill the Prophet's guards and find a way off the ship. Learning that there is no way to change the Forerunner ship's destination, the Chief jumps to Earth using a piece of the vessel as a heat shield.
After informing the UNSC about the true nature of the Key, Ruwan volunteers to "give" the Key to the Covenant. He is captured and brought aboard a Covenant ship. While the Covenant believe he is to be rescued due to a tracker embedded in him, Ruwan reveals he is actually a target. A
coilgun takes aim at his position and destroys the ship. Upon learning that the Key is a fake, the Brutes on Mars behead Ackerson. In a relief camp, Tyla writes a song about Ruwan.
