“Yes. The London smell is not to be confused with the smell of any other place. You have been back a good while, I believe?”

“Three years. I am laid on the London shelf now.”

“You have had a long life of work—interesting work.”

“Yes. Diplomacy has interesting moments. I have seen many countries. I have been transferred from Copenhagen to Teheran, visited the Sultan of Morocco at Fez, and—” he stopped. After a pause he added: “And now I sit in London clubs and look out of bay windows.”

They walked on slowly.

“Have you known our hostess of to-night long?” Sir Donald asked presently.

“A good while—quite a good while. But I’m very much away at Rome now. Since I have been there she has married.”

“I have only met her to speak to once before to-night, though I have seen her about very often and heard her sing.”

“Ah!”

“To me she is an enigma,” Sir Donald continued with some hesitation. “I cannot make her out at all.”