"Why did you tell me that Mr. Theydon was a serious scientific
person?" cried the girl. "He is anything but that. He can talk
nonsense quite admirably."

"So can a great many serious scientific persons, Evelyn. Glad to see
you, Mr. Theydon. Professor Scarth's letter paved the way for
something more than a formal meeting, so I thought you wouldn't mind
giving us an evening. My wife is not in town. She is a martyr to hay
fever, and has to fly from London to the sea early in May to escape.
If caught here in June nothing can save her. Tonight, as it happens,
you're our only guest, but my daughter is going to a musicale at Lady
de Winton's after dinner, so you and I will be free to soar into the
empyrean through a blaze of tobacco smoke."

Standing there, in that delightful drawing room, made welcome by a man
like Forbes, and admitted to a degree of charming intimacy by a girl
like Forbes's daughter, Theydon tried to believe that his meeting with
those ill-omened detectives at Waterloo Station was, in some sort, a
figment of the imagination.

But he was instantly and effectually brought back to a dour sense of
reality by Evelyn Forbes's next words. She, by chance, looked at
Theydon just as she had looked at him the previous night.

"Were you at Daly's Theater last night?" she inquired suddenly.

"Yes," he said. Then, finding there was no help for it, he went
on:----

"You and I have hit on the same discovery, Miss Forbes. We three stood