her form when she is thinking. Halsey sees Cortana as a teenage version of herself: smarter than her parents, always "talking, learning, and eager to share her knowledge". Cortana is described as having a sardonic sense of humor and often cracks jokes or wryly comments, even during combat. Appearances In video games Cortana's first game appearance is in 2001's Halo: Combat Evolved. Humanity is locked in a losing war with the alien Covenant. Cortana plots a course for the human ship Pillar of Autumn to escape the Covenant. This heading leads to the discovery of a massive ringworld, Halo, built by a mysterious race known as the Forerunners. Cortana defends the ship from the Covenant until she is given to the supersoldier Master Chief to prevent her from falling into enemy hands. Cortana helps direct human survivors scattered across the ring and assists the Master Chief in his missions. Inserted into Halo's Control Room, Cortana realizes that the ring serves as a prison for the parasitic Flood; activating Halo would mean destroying all sentient life in the galaxy to prevent the Flood's spread. Cortana assists Master Chief in destroying the ring and escaping. In Halo 2, Cortana assists in the defense of Earth in the wake of a Covenant attack. Cortana, Chief and human forces travel to another Halo ring, Delta Halo, where Master Chief and Cortana encounter the Flood intelligence Gravemind. The Gravemind sends Chief and Cortana to the Covenant city-ship of High Charity to stop the Covenant from activating Halo; Cortana ultimately stays behind on High Charity to destroy the city and Halo should Master Chief fail in his mission. High Charity and Cortana are captured by the Flood. In Halo 3, Cortana appears to the player in broken transmissions. On the Forerunner installation known as the Ark, the Master Chief travels through the ruins of High Charity to rescue Cortana. Chief and Cortana are successful at stopping the Flood, but become stranded in deep space aboard the human ship Forward Unto Dawn. Cortana activates a distress beacon, while Master Chief goes into cryonic sleep to await rescue. At the beginning of Halo 4 Cortana wakes the Chief as Forward Unto Dawn drifts towards a Forerunner installation called Requiem. Cortana begins displaying aberrant glitches and behavior, and reveals that she is suffering from rampancy as she approaches the end of her seven-year lifespan. She assists in the battle