Look at this chap, angelically reading the lesson in chapel, some years ago.
He is now 15.
This week he returned to his old school, to help out for a few days.
At some point during the first day, he found a way to set off a smoke machine, in the science labs, that caused the Headmaster to have to intervene and remove it.
When David went to collect Amory the headmaster came out to meet him. He felt that one day, rather than the offer of a week of Amory, was just about right.