Michael was a little perturbed in mind. He took a more serious view of the closed car than did the girl, and the invitation to the “pretty lady” to step inside was particularly disturbing. Since the events of the past few days it had been necessary to withdraw the detective who was watching the girl’s house, and he decided to re-establish the guard, employing a local officer for the purpose.

After he had driven Adele home, he went to the police station and made his wishes known; but it was too late to see the chief constable, and the subordinate officer in charge did not wish to take the responsibility of detaching an officer for the purpose. It was only when Michael threatened to call the chief on the telephone that he reluctantly drew on his reserves and put a uniformed officer to patrol the street.

Back again at Knebworth’s house, Michael examined the two articles which the girl had found. Butyl chloride was a drug and a particularly violent one. What use would the Head-Hunter have for that, he wondered.

As for the handcuff, he examined it again. Terrific force must have been employed to snap the connecting links. This was a mystery to him, and he gave it up with a sense of annoyance at his own incompetence.

Before going to bed he received a ’phone message from Inspector Lyle, who was watching Griff Towers. There was nothing new to report, and apparently life was pursuing its normal round. The inspector had been invited into the house by Sir Gregory, who had told him that Bhag was still missing.

“I’ll keep you there to-night,” said Michael. “To-morrow we will lift the watch. Scotland Yard is satisfied that Sir Gregory had nothing to do with Foss’s death.”

A grunt from the other end of the ’phone expressed the inspector’s disagreement with that view.

“He’s in it somehow,” he said. “By the way, I’ve found a bloodstained derby hat in the field outside the grounds. It has the name of Chi Li Stores, Tjandi, inside.”

This was news indeed.

“Let me see it in the morning,” said Michael after long cogitation.