“I'm glad of that,” replied Giles, pressing the front door bell. “Roger was in England at the time of the murder. Is that it?”

“Yes,” said Hannasyde. That is it.”

“Poor old Roger!” remarked Giles. “I rather suspected he was when he forgot the name of his ship.”

Hannasyde bent an accusing stare on him. “You're as bad as the rest of them,” he said severely. “The instant you set eyes on Roger Vereker you not only suspected that he'd been in England some time longer than he admitted, but you were pretty sure also that he was the shabby stranger who visited Arnold Vereker that Saturday. Isn't that true?”

“Not quite,” said Giles. “I suspected it several hours before I set eyes on him. As soon as I heard he had turned up, in fact. Good afternoon, Murgatroyd. Miss Tony in?”

“Oh yes, she's expecting you, sir,” said Murgatroyd, holding the door wide. “But what call you've got to bring the police back again I'm sure I don't know. Seems as though we can't call the place our own these days. They're both in the studio, Mr Giles.”

Giles Carrington nodded, and walked across the little hall, followed by the Superintendent. In the studio Roger Vereker was apparently working some problem out on scraps of paper, critically but not unamiably watched by his half-sister, who sat with her chin in her hands, looking over his calculations. She glanced up quickly as the door opened, and, when she saw Giles, smiled in her confiding way. “Hullo!” she said. “Roper's trying to work out a System. I think it's all rot myself.”

“Long may you continue to think so,” said Giles.

Antonia perceived Superintendent Hannasyde, and raised her brows. “I didn't know you were coming too,” she said. “I rather wish you hadn't, because, to tell you the truth, I'm getting awfully sick of the Family Crime. However, come in if you must.”

“I'm afraid I'll have to,” answered Hannasyde, closing the door. “I want to ask your half-brother a few questions.”