The Belgian artist Alÿs collaborated with the National Portrait Gallery to create a piece generated by the gallery's state-of-the-art internal CCTV system. Alÿs released a fox, called Bandit, into the deserted gallery at night. Seen from the high viewpoint of the security cameras, the fox looks a little puzzled among all the paintings of the great and the good. Like the guards, he is out of context; an intruder, observed dispassionately.