 On board 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 . 
