Still, even if the telephone message could be discredited—and Ellery realised that this would take some doing—there remained the walking-stick, and the undoubted fact that Walter Brooklyn had expressed the intention of seeing Prinsep that evening. They could not feel that the evidence which they had so far gathered made his acquittal even probable, much less secure, especially as there was still no evidence that seemed to point in any other direction. Joan and Ellery felt that they must get further confirmation of the _alibi_. It was a question of accounting, not for a few minutes here and there, but for every minute of Walter Brooklyn’s time. Clearly, what now mattered most was where he had been between the time when the old night-watchman saw him in Piccadilly Circus and his return to his Club at about midnight. George Brooklyn had been seen alive as late as 11.30, and Prinsep only a few minutes before. If Walter Brooklyn had murdered either, it must have been done between 11.30 and midnight; for it seemed clear enough that he had not left his Club again during the night. Of this the night porter was positive. At the same time, it was desirable, though less important, to confirm also his story of his movements during the earlier part of the evening. After they had talked the situation over, Joan and Ellery determined to pursue the hunt together, and once more to follow Walter Brooklyn’s route in search of further confirmation. For what it was worth, Joan had already been able to confirm her stepfather’s first statement about his movements. A door porter at the Piccadilly Theatre had seen him standing for a minute or two outside the main entrance “a bit before half-past ten,” and had noticed him walking off along Piccadilly towards the Circus. Thereafter, although Joan and Ellery hunted high and low, they could get no further trace of him until his meeting with Kitty Frensham in Leicester Square at a quarter to eleven. They found and interrogated without success the policeman who had been on duty in Piccadilly Circus. They even inquired of the porter outside the Monico and the Criterion and of a few street sellers who were standing at the corners. There was no information to be obtained; but they agreed that this did not greatly matter, if only they could get evidence bearing on Walter Brooklyn’s movements after half-past eleven, or still better, from 10.45 onwards. They would begin at the other end, and try to trace his movements between 11.30 and midnight. Accordingly, they walked down together to Trafalgar Square. Here there were two possible lines of investigation. Walter Brooklyn had first leaned for some moments over the parapet opposite the National Gallery: he had then walked down to the top of Whitehall, and had there paused to set his watch by a clock standing out over one of the shops. There was a slender chance that some one might have noticed him on one or other of these occasions.