Lorna raised an eyebrow at his entirely unnecessary permission. Did he think that because she was young she was going to be one of those 'we're all pals' professors? God, she hoped not. "Have a seat, Mr. Lehnsherr. Unless it's about an extension, in which case the answer is no."

The homework shouldn't have required that much explanation. It was a matter of simply establishing the mathematics to be used in the course and a few examples to work through.