The Doctor's TARDIS (Exile)

In a parallel universe, the Doctor stole a TARDIS when they first fled Gallifrey. When their second incarnation was tried by the Time Lords, they managed to return to their craft and escape, regenerating into a female incarnation to hide. Landing on Earth, the Doctor abandoned the TARDIS and removed its Time Vector Generator to better hide it from the Time Lords while the Doctor went out of her way to try to adapt to a human life.

When the Doctor was recaptured, she was later sentenced back to the TARDIS since she had embarrassed the Time Lords by escaping their justice. Originally she was to be exiled to Earth in the first place, but with the escape, it had elevated to death. She would be confined to the TARDIS to live there for the rest of her life, and if she tried to escape it would dematerialise, erasing her history.

One of the Time Lords claimed to sympathise with her plight and told her in a note she had a way out. The note told her the TARDIS was not rigged to erase her history. As she set the controls and began to leave in the TARDIS, the Doctor wondered if the note was genuine. (AUDIO: Exile)