The duo saw this as a solution to destroy the Flood on the Ark, and John-117 recovered Cortana from High Charity, where she revealed that she had Alpha Halo's Index in her memory banks.
This act put the Halo Array on standby mode, allowing them to be activated from Installation 00 (The Ark).ĭuring the Battle of Installation 00, John-117 and Thel 'Vadam discovered a newly constructed Alpha Halo. Tartarus is then killed by Thel 'Vadamee and Johnson, and Commander Keyes was able to pull the Index out of the Control Room. He was interrupted by Thel 'Vadamee's return, and after 'Vadamee's attempt to convince Tartarus that the Prophets had betrayed him, he forced Keyes' hand into the Index to activate it. Knowing he needed a " Reclaimer" to activate the Forerunner installation, he took Keyes to Delta Halo's Control Room where he attempted to force her to activate the ring. Tartarus then took the Sacred Icon to the Hierarchs, and the High Prophet of Truth ordered Tartarus to activate Halo and initiate the Great Journey. Johnson lost it to Tartarus and his Jiralhanae when they were ambushed by Thel 'Vadamee. In the course of obtaining the Index, she and Sergeant Avery J. In an effort to stop the High Prophet of Regret from activating Delta Halo, Commander Miranda Keyes proceeded to the Installation's Library to acquire the Index. The Index appeared again in Halo 2, although it was for Installation 05. After John-117 breaks up their argument, Cortana explains to him the true function of Halo. Cortana then begins to argue with 343 Guilty Spark about the course of action to take concerning the Flood. The "Sacred Icon" is first seen in Halo: Combat Evolved where, with the help of 343 Guilty Spark, John-117 located and attempted to activate Halo, but was stopped just before inserting the key by Cortana.
The object seems to be merely a digital storage device containing the software or access codes needed to activate the rings, as shown when Cortana activates the second Installation 04 with the Index stored in her memory. (In Halo 2, the Index not only glows green, but it also glows a blue color.) It is approximately 60 centimetres (2.0 ft) long. The Index is vaguely ' T'-shaped, with a faint green glow emanating from a stripe on each side. The rings are also used to house the Flood and keep them contained. The purpose of the Halo Rings is to destroy all sentient life in the galaxy, the Flood's food source, so that the Parasite would starve to death. Only one firing of the rings occurred, at the close of the Forerunner-Flood war. Halo's main weapon exists primarily in case the Flood manage to escape containment and spread their infection to other planets. John-117 noted in his debriefing of the Halo event that, if not for Cortana's intervention, he would have accidentally activated the weapon and destroyed all life in the galaxy. This may be found in all of the libraries on all seven Halos.
The reason Alpha Halo's Index worked on the replacement ring at the Ark was because they were both Installation 04. It is confirmed that an Index cannot be used to activate any Halo besides the one it is found on. When inserted into the Core of the Ring, the Index activates the Installation's main weapon. It is the key needed to activate the Installation, causing a reaction that will purge the galaxy of all sentient life. The Activation Index, the Key, or Sacred Icon as the Covenant call it, is an object found in every Installation's Library. Were you looking for Sacred Icon, a Halo 2 level?