Charley Pollard
After being stranded in the far future following her adventures with the 8th Doctor, her distress call was answered by the right TARDIS, just the wrong Doctor. Her travels continued with the 6th incarnation, without telling him who she was. Fighting the Daleks, Viyrans and meeting the Draconians, her secret remained and her travelling ended during that fatefull time on the Blue Forgotten Planet.