I have been too long in London, she thought; I must have a change. Find a hotel on the South Coast, perhaps. Or go abroad. One forgets that the world is young.

"Who is singing?" she asked, as her cup was handed to her again.

"Stewart, I think," Dr Knight said, not interested. "Miss Pym, you can save my life if you like to."

Lucy said that to save a doctor's life would give her immense satisfaction.

"I want to go to a medical conference in London," Dr Knight said in a conspiratorial undertone. "It is on Thursday, but that is the day of my psychology lecture. Miss Hodge thinks I am for ever going to conferences, so I can't possibly beg off again. But if you were to take that lecture for me, everything would be grand."

"But I am going back to London myself tomorrow after lunch."

"No!" said Dr Knight, much dashed. "Do you have to?"

"Oddly enough, I was just thinking how much I should hate going back."

"Then don't go. Stay on for a day or two, and save my life. Do, Miss Pym."

"And what would Henrietta think of the substitution?"