Tannis's TARDIS
Tannis secretly had access to a TARDIS with a functional cloaking system which made it invisible.
He had it disguised in the government buildings on Alpha Canis One. After murdering Antimony in front of the Seventh Doctor, he used it to travel back to his command ship in orbit around Santiny — appearing to vanish into thin air as he stepped into the invisible ship and then made it dematerialise. After tipping the Minister over the edge by ordering Senator Sala's death, then commanding the fleet to pull out from Santiny and head for Earth, (WC: "No Child of Earth" [+]Part of Death Comes to Time, Loading...{"namedep":"No Child of Earth","1":"Death Comes to Time (webcast)"}) Tannis briefly travelled to Gallifrey to confront and murder Castellan Casmus on the slopes of Mount Plutarch. He then rejoined his fleet in time for the invasion of Earth, coming down to the planet in his command ship's landing craft rather than his TARDIS. The TARDIS was presumably lost as Alistair Gordon Lethbridge-Stewart's forces finished destroying the orbital fleet. (WC: "Death Comes to Time" [+]Part of Death Comes to Time, Loading...{"namedep":"Death Comes to Time","1":"Death Comes to Time (webcast)"})
