“Manderton knows I am in Rotterdam,” he explained, “and he promised to wire me the latest developments in the enquiry he is conducting.”

“Miss Trevert should be fully recovered by this,” put in the doctor; “apart from a little sickness she is really none the worse for her disagreeable experience. If there was anything you wanted to ask her ...”

“There is,” said Robin promptly. “Her reply to one question,” he explained, turning to Herr Schulz, “will give us the certainty that Parrish was murdered and did not commit suicide. It will not delay us more than five minutes to stop at her hotel in passing, We will then call in at my place. We should be at the Villa within half an hour from now ...”

“Gentlemen,” said Herr Schulz as they prepared to go, “I know my Mr. Victor Marbran. You should all be armed.”

Robin produced the pistol he had taken from Jeekes. Herr Schulz slipped a Browning pistol into the breast-pocket of his jacket and, producing a long-barrelled service revolver, gave it to the doctor.

“There are three of them, I gather, counting the chauffeur,” commented the big man, pulling on his overcoat, “so we shall be equally matched.”

Darkness had fallen upon Rotterdam and the lights from the houses made yellow streaks in the water of the canal as the car, piloted by Robin, drove the party to Mary Trevert’s hotel.

They found the girl, pale and anxious, in the lounge.

“Well, now,” cried the doctor breezily, “and how are you feeling? Did you take my advice and have some tea?”

“What has happened?” asked the girl; “I have been so anxious about you ...”