Matrix door

A Matrix door was a method of physically entering the Matrix on Gallifrey, as opposed to merely connecting one's mind to the Matrix. (TV: The Deadly Assassin) The sensation of passing through a Matrix door felt like being "scanned."

A number of these doors existed, with particular ones including a Matrix access door within the Vaults on Gallifrey, (AUDIO: Lies) the legendary Seventh Door outside the courtroom on Space Station Zenobia through which the Sixth Doctor, Mel, and Sabalom Glitz pursued the Valeyard, (TV: The Ultimate Foe) and the Eighth Door which simultaneously existed onboard the Doctor's TARDIS which Ace used, (PROSE: St Anthony's Fire) and onboard the Time Station through which President Romana II came in contact with Rassilon. (AUDIO: Neverland)

The Valeyard hid another matrix door on the mudball planet orbiting Eta Rho, using it to escape the particle disseminator trap left for the Sixth Doctor and Inquisitor Darkel. (AUDIO: Trial of the Valeyard)