Drake watched her set a foot upon the rail of the fender, lay her hand upon the mantelshelf and support her forehead upon it.

After a little she raised her head and spoke with an air of apologising for him.
'Of course,' she said.

'You could not know that there was anything between myself and--and him.' 'No; I could not know that.

How should I, for I did not know you?
And I am glad that I didn't know.' Drake spoke with some earnestness, and Clarice looked at him in surprise.
'It would have made my duty so much harder to do,' he explained.
With a little cry of irritation Clarice slipped her foot from the fender and moved from him back to the couch.

She had given him the opportunity to escape from his position and he refused to make use of it; he seemed indeed unable to perceive it.