Ace was standing at the Tardis console on there way to another adventure when Ace felt odd sensation thought her body and things going dark, "Professor what happening?!" thing we're going dark around her as images of the tardis disappeared.
She thought that this was the end or something to do with the master and his evil ways as Ace found herself waking up on earth of all places on what looks like a docks in the pouring rain, Ace walked up to the nearest door and bang on it see if any one was home.
Or if not to seek shelter from the rain that still continue to thrashing down and spotted a cctv camera and look at it and shouted "OPEN UP" as Ace continued to bang on the door.