Airing in 1976, years before The Matrix was made, before William Gibsons novel Neuromancer was published, even before the advent of virtual reality in the 1980s, Doctor Who was doing battle inside the Matrix. Yes, the four part serial The Deadly Assassin sees the Doctor go head to head with Chancellor Goth inside a simulated reality called the Matrix that is accessed through apparatus connected to the users head. The physical laws of this simulated reality can be manipulated by the more experienced users, with the most advanced able to bend and break the laws entirely. The President of the High Council of Time Lords is the only person with strictly unlimited access to the Matrix, which holds the biological imprints of every Time Lord, living or dead, and also receives data from sensors contained in the TARDIS time machines used by Time Lords to travel through time. The upshot of all this is that the Matrix is not just a record of the past, but a way of predicting the future. Similarly to the Wachowskis Matrix, this virtual world is neither complete nor fool-proof, and can be tampered with when accessed by someone with the right skill set. Though not originally presented as a place with an ominous purpose, a Past Doctor Adventures novel by Mike Tucker and Robert Perry reveals that a Dark Matrix actually exists, containing the evil impulses of every Time Lord from history, hidden and forgotten about. When The Valeyard manage to take control of the Dark Matrix and attempt to use it to manipulate the Doctor's timeline, it is up to him to destroy it.
