The taxi wound its way slowly through the thronging traffic. The gloom of a late winter afternoon had set in, and the street lamps, which had just been lighted, only illuminated fitfully the corner in which Harper sat. Mallett looked at him curiously. The pose suggested to his experienced eyes a sense of strain, as though the young man was compelling himself to appear at ease, without altogether succeeding. His head lolled back comfortably enough against the back of the car, his legs were jauntily crossed, but at the same time there was to a close observer a rigidity in the body which told of muscles that were taut with the effort of doing nothing, of nerves protesting against the ordeal to which they were being subjected. None the less, the inspector looked in vain for any sign of the acute terror which their encounter at Brighton had so unmistakably inspired. Then he had been frightened—horror-struck, almost; now he was ill at ease, nervous perhaps, but no more. Here was an enigma, and one that the inspector determined to resolve without delay.

“The last time I saw you,” he began, “you seemed to be enjoying yourself.”

“Enjoying myself?” echoed Harper in apparent surprise. “That seems rather an odd way of putting it.”

“I don’t see anything odd about it,” returned Mallett. “It would have been my idea of enjoying myself, at your age, and most people’s, too.”

“People’s ideas of enjoyment evidently differ. I really can’t answer for yours. Personally, I found it a most distasteful experience, and I thought I made it clear at the time.”

“No, I’m damned if you did!” exclaimed Mallett, irritated at this absurd piece of fencing. “If ever I saw a young couple enjoying themselves——”

“Really, Inspector,” Harper broke in, “I think we are talking at cross-purposes. Now I come to think of it, you mentioned the last time you saw me. Strictly speaking, I have no idea when that was. As a detective you may, for all I know, make a practice of seeing people when they aren’t looking. I can only speak of the last time I saw you, and that was at the inquest.”

The taxi travelled some distance before Mallett found words to answer this extraordinary assertion.

“Are you going to deny that you were at the Riviera Hotel, Brighton, the evening after the inquest?” he asked sternly.

“Certainly not. Why should I?”

“And that you saw me there—in the interval between two dances—and seeing me, showed every sign of surprise and fright, and”—he paused for greater emphasis—“and guilt?”

Harper’s manner had changed completely. Abandoning altogether his attitude of defensive suspicion, he now leant forward and spoke with an appearance of entire sincerity.