BARBARA: You don’t care about anyone, do you? Everyone’s just a – a chess piece, to you, now that Susan’s gone. Ian, me –

DOCTOR: My dear Susan –

BARBARA: I am not Susan! Nor am I a piece of Susan, whatever you’ve told the Venusians. Neither is Ian. We’re people – people who are travelling with you, and through no choice of our own. You have a responsibility to us. If you can’t get us home, very well. But at least you can look after us in the meantime. Or if you won’t – if you’re too busy with your ’mysteries' – then we’ll just have to look after ourselves.