The Doctor realized that he had not had time to analyze the blood from the previous planet. That bothered him. There could have been clues there, important ones. He sighed.
It seemed Eleni assumed this was a psychological experiment. The Doctor wasn't sure that was the actual case. He did think it was unlikely that their captors would single Phaedra out to suffer unduly, though.
"I don't think they'd single you out as the being not to be able to eat," he offered. "I think that, if you couldn't nourish yourself, we would also be without food. Keep the terms equal."