She moved swiftly into his study and he followed her. They heard Nash come out and open the door. They listened, almost in sympathy with each other. “Sir Derek and my lady are not at home, madam.”

“But there’s a light in the study!” They exchanged horrified glances.

“Perhaps Mr. Jameson— ” said Nash.

“Just the man I want to see.”

They heard Nash bleating in dismay and the sound of Miss Ruth O’Callaghan’s umbrella being rammed home in the ship’s bucket. With one accord they walked over to the fireplace. Lady O’Callaghan lit a cigarette.

The door opened, and Ruth came in. They had a brief glimpse of Nash’s agonised countenance and then were overwhelmed in embraces.

“There you are, darlings. Nash said you were out.”

“We’re only ‘not at home,’ Ruth darling,” said Lady O’Callaghan, very tranquilly. “Derek expects his doctor. It was too stupid of Nash not to realise you were different.”

“Ah-ha,” said Ruth, with really terrifying gaiety, “you don’t defeat your old sister like that. Now, Derry darling, I’ve come especially to see you, and I shall be very cross and dreadfully hurt if you don’t do exactly what I tell you.”

She rummaged in an enormous handbag, and fetched up out of its depths the familiar sealed white parcel.

“Really, Ruth, I can not swallow every patent medicine that commends itself to your attention.”

“I don’t want you to do that, darling. I know you think your old sister’s a silly-billy”—she squinted playfully at him—“but she knows what’s good for her big, famous brother. Cicely, he’ll listen to you. Please, please, persuade him to take just one of these teeny little powders. They’re too marvellous. You’ve only to read the letters— ”

With eager, clumsy fingers she undid the wrapping and disclosed a round green box decorated with the picture of a naked gentleman, standing in front of something that looked like an electric shock.