destroying the ring and preventing the Flood from escaping. The Flood returns in Halo 2 (2004), appearing on another Halo ring called "Delta Halo". The Flood on Delta Halo is led by the Gravemind, a massive Flood intelligence that dwells in the bowels of the ring. Gravemind brings together the Master Chief and the Covenant holy warrior known as the Arbiter and tasks them with stopping the Covenant leadership from activating the ring. In the meantime, Gravemind infests the human ship In Amber Clad and crashes it into the Covenant space station of High Charity. Once there, the Flood sweeps through the city, and the Gravemind captures Cortana. As the Flood spreads, the Covenant form a blockade in an effort to prevent the parasite from leaving its prison. The Flood reappears in the Halo 3 mission "Floodgate", on board a damaged ship that escapes the quarantine around Delta Halo. While the infestation of Earth is prevented, Master Chief and Arbiter form a tenuous alliance with the Flood to stop the activation of all the Halo rings at the Forerunner installation known as the Ark. Once the threat is stopped, the Gravemind turns on them. The Master Chief fights his way to the center of High Charity, freeing Cortana and destroying the city, but Gravemind attempts to rebuild itself on a Halo under construction at the Ark. Realizing that activating the ring will destroy only the local Flood infestation due to the Ark's location outside of the Milky Way, the Master Chief, Arbiter, and Cortana proceed to Halo's control room, activate the ring, and escape. The Gravemind warns them that his defeat will only delay the Flood, not stop it. The Flood also makes an appearance in the video game spinoffs Halo Wars and Halo Wars 2. In Halo Wars, they are encountered infesting a Forerunner installation and ultimately annihilated by the actions of the human ship Spirit of Fires crew. In the Halo Wars 2 expansion "Awakening the Nightmare", the surviving Flood were accidentally released by the Banished while salvaging the wreck of High Charity. The Flood also serves as an enemy in the game's cooperative "Firefight" mode. The Flood also appear in cooperative play in Halo: Spartan Assault. With Halo 3, the developers added a multiplayer gametype called "Infection", a last man standing mode based on a fan-created scenario where human players defend against Flood-infected players, with each slain