The Matrix


 * For the novel, see Matrix (novel).

The Matrix (or the Matrix) was a domain within the APC Net (Amplified Panatropic Computer Network), a supercomputer used by the Time Lords (specifically the High Council) both as a storehouse of knowledge and to predict future events. The terms APC Net and Matrix were often used interchangeably.

Creation
Rassilon entered into the Matrix after his death (or "death"). Here, he and a council of High Evolutionaries or "Matrix Lords" monitored events in the outside universe. (DWM: The Tides of Time onwards) The legendary Dark Matrix, however, was a repository of all the dead Time Lords' most evil thoughts. (PDA: Matrix)

Uses of the Matrix
Returned to Gallifrey by Councillor Goth, the Master made secret use of the Matrix, infilitrating it and using Goth as his agent within it. Goth confronted the Doctor there, and attempted to kill him. (DW: The Deadly Assassin)

As Lord President, the Doctor used the Matrix to gain access to the secrets needed to defeat the Sontaran invasion of Gallifrey, specifically the De-mat Gun. (DW: The Invasion of Time) While connected to the Matrix, he learned of the existence of the Timewyrm, and left a message for himself warning of this threat. (NA: Timewyrm: Genesys)

After his supposed execution to stop Rassilon's exiled contemporary Omega from returning to the universe of matter, the Doctor hung suspended there. Omega also had access to the Matrix. (DW: Arc of Infinity)

The Valeyard established a stronghold, the "Fantasy Factory", in the Matrix as part of his plan to steal the Doctor's remaining regenerations. During his attempt to stop him, the Doctor, as well as the Master, entered into the "dreamscape" contained therein, the latter taking his TARDIS (or an illusory version of it) there. The Valeyard then somehow took over the Keeper of the Matrix. (DW: The Ultimate Foe)

The Doctor confronted the Dark Matrix, which was trapped inside a TARDIS as it imploded. (PDA: Matrix)

Conflicting accounts of the fate of the Matrix
An ancient Gallifreyan evil named Pandora also survives and emerges from a special partition within the Matrix. Lady President Romana was eventually able to destroy the entity by destroying the Matrix itself. (BFG)

Another account says that Gallifrey was destroyed by the Eighth Doctor to prevent the voodoo cult Faction Paradox from starting a time war between the Time Lords and an unspecified Enemy. (EDA: The Ancestor Cell) It was later revealed that the Time Lords had survived within the Matrix, which had then been downloaded into the Doctor's mind, although he had to sacrifice much of his memory to make space for it. Their reconstruction was possible, but would require a sufficiently advanced computer. The question of whether or not the Time Lords would be restored remains unanswered. (EDA: The Gallifrey Chronicles)


 * This event may take place in an alternative timeline or in the future, relative to the other event, given that by this time, Romana had regenerated into a third incarnation. Possibly both they and the planet are restored at some point before Gallifrey's later destruction.

Characteristics
The Matrix, specifically, contained a simulated reality environment, once described as a "micro-universe" (DW: The Ultimate Foe) which served as storage for the personalites of Time Lords now without physical bodies. Living beings could also access the Matrix. The terms Matrix and APC Net, however, have sometimes been used interchangeably.

Physically, the Matrix stored the memories of dead Time Lords, storing them in a framework electrochemical cells. (DW: The Deadly Assassin) It also received input from sensors contained within TARDISes. (PDA: The Quantum Archangel) The Matrix is not only a record of the past, but can actually predict the future as well. The amount of knowledge in the Matrix, though vast, is not complete, and can be tampered with if given the right amount of access. The unauthorised extraction of a Time Lord's bio-data from the Matrix is an offence tantamount to treason. (DW: Arc of Infinity) In fact, a particularly skilled person such as the Valeyard could create images of false events that never had and never would happen. (DW: Mindwarp, Terror of the Vervoids, The Ultimate Foe)

The environment of the Matrix
To living beings, the Matrix could appear relatively like conventional reality (DW: The Deadly Assassin, The Ultimate Foe), a surreal dream (DWM: The Tides of Time), a dark void (DW: Arc of Infinity), or first in one state, then giving way to another. Basic physical laws remain malleable, able to be bent or broken, according to the will of the inhabitant. The more experience with the Matrix and the greater the will of the occupant, the greater the control over the local "reality".

Beings known as the Matrix Lords, including Rassilon himself, "lived" here and could direct actions from within it. For example, they created a physical agent, Shayde, to act for them in the outside world. (DWM: The Tides of Time)

Physical access
Access to the Matrix is obtained through an apparatus connected to or enclosing the head of the user. (DW: The Deadly Assassin) The Crown of Rassilon worn by the Lord or Lady President provides to them instant access. (DW: The Invasion of Time) The Keeper of the Matrix held the Key of Rassilon that granted access to the Seventh Door, which was thought legendary until the Doctor used the Key to access it. The Seventh Door allowed physical access to the Matrix by living persons. (DW: The Ultimate Foe)