"Isn't it funny," said Isabel meditatively, "how one person can make such a lot of difference? Paul Seaton goes away for a day or two, and London becomes as sparsely populated as the steppes of Russia and as desolate as the Great Sahara; Paul Seaton comes back again, and the place is as crowded as if it were the scene of a Jubilee procession or a royal wedding."

"Thank you," said Paul simply.

"I am going to bring out a new arithmetic book," continued Isabel, "with problems such as these: Take one from five millions and only one remains—and that one is yourself and very lonely."

Paul laughed, and Isabel rattled on: "Add one to two, and the result is still two; for the one is sadly de trop, and so is shaken off as soon as possible".

"What a clever mathematician it is!" said Paul fondly.

"You are rather a swell at mathematics yourself, aren't you?" asked Isabel.

"I wasn't bad at them when I was at Oxford."

"Yet, my dear Paul, you are very slow at putting two and two together. I have often noticed it."

"Because that is a higher branch than those in which I was proficient. But wherein have I failed lately to satisfy the examiners on this score?"

"You don't always understand women—me, I mean."