The Doctor's eyes moved to the silvery robot behind them, and his first reaction was to tell Jack not to move. Don't move, the Raston Warrior Robots are based on movement and they'd see him if he moved.

But he couldn't, the words were caught in his throat. He couldn't even move his lips, he just sat there, frozen. He tried, desperately, to tell Jack to stay still with his eyes. Stupid stupid stupid poisoned food!

The robot fired an arrow the moment Jack fell.

The Doctor couldn't even make a cry of protest.