Thief of Time - See

'Well, of course... no, not... in many ways...' she began, and became aware that Miss Susan was staring past her. There was... Madam Frout groped for her glasses, and found their string had got tangled with the buttons of her blouse. She peered at the mantelpiece and tried to make sense of the blur.

'Why, it looks like a... a white rat, in a little black robe,' she said. 'And walking on its hind legs, too! Can you see it?'

'I can't imagine how a rat could wear a robe,' said Miss Susan.

***

The Thief of Time - p76