“And what now?” asked Julius, with a gesture of despair. “I guess we’re down and out for good.”

Sir James stroked his chin thoughtfully.

“No,” he said quietly. “There is still the chance that Dr. Hall may be able to tell us something.”

“Gee! I’d forgotten him.”

“The chance is slight, but it must not be neglected. I think I told you that he is staying at the Métropole. I should suggest that we call upon him there as soon as possible. Shall we say after a bath and breakfast?”

It was arranged that Tuppence and Julius should return to the Ritz, and call for Sir James in the car. This programme was faithfully carried out, and a little after eleven they drew up before the Métropole. They asked for Dr. Hall, and a pageboy went in search of him. In a few minutes the little doctor came hurrying towards them.