Genesta's TARDIS

Genesta operated a TARDIS when she helped the Sixth Doctor against a plot by the Valeyard from displacing all of the Time Lords in the Matrix with copies of himself with the help of microscopic telepathic beings known as the Nathemus.

The Doctor complimented Genesta on her TARDIS, describing it as "nifty" although he had problems with the telepathic circuits when he came up with a plan to use them to send a message to his younger self in an earlier version of his own TARDIS to alter course so then he would pass through a cloud of radiation around Lakertya that was harmful to Time Lords so then the Nathemus who was feeding off of his own unique mind would die when he regenerated.

During the process, Genesta transformed into the Valeyard. The Doctor was certain Genesta was real because she was nothing like the Valeyard, and while the Valeyard mocked him about his infatuation with Genesta because she reminded the Doctor of himself he didn't confirm or deny the Doctor's beliefs either way.

When this version of the Sixth Doctor returned to the Matrix with the Valeyard, it is unknown what became of this TARDIS. (AUDIO: The Brink of Death)