His thoughts turned to Cosgrove Ponson. Here was another man who had an interest in Sir William’s death. And from what Mr Arbuthnot had said, his interest might be quite as strong, or even stronger, than Austin’s. When a man about town who had been living a rather fast life got into financial difficulties, he was not usually very squeamish as to how he extricated himself. £75,000 to a man perhaps faced with ruin would be worth taking a risk for. And if Cosgrove had become hardened enough to commit the crime, he would probably not have jibbed at making the plant to throw the suspicion on Austin. Tanner concluded that if Austin’s alibi held, his next work must be the investigation of Cosgrove’s life as well as his movements on the night of the murder. His whole cogitations therefore simply brought him back to the point from which he had started. Before he did anything else, every point of Austin’s alibi must be gone into with the most meticulous care. Accordingly, having refilled his pipe, he set himself to go over in detail the story Austin Ponson had told him of his movements on the night of the murder. He wished not only to be clear in his own mind as to the sequence of events, but to make a list of the points upon which he could reasonably hope to obtain confirmatory evidence. Austin, according to his own statement, left the pavilion of the Halford boat club at about ten minutes before nine. He rowed to the Old Ferry, sat there for about ten minutes, until the maid arrived with the note, then walked to the Abbey and spent a few minutes searching for Miss Drew and her friends. Failing to find them, he went to the Franklyns’ house, satisfied himself it was empty, returned to the Old Ferry, and rowed back to Halford, arriving at the pavilion about quarter before eleven. There he had waked the caretaker to get the boat in. He had walked to the Drews’, stayed with them some ten minutes, going on to his own house, which he reached about twenty minutes past eleven. Now, first, as to the checking of these hours. Tanner took a sheet of paper, and looking up his note of the times it had taken him to walk the various distances, and estimating for the rowing, he made a statement something like a railway time table. When he had finished he found that the total estimated time which the journeys should have taken worked out at practically that mentioned by Austin. So far, then, the story hung together. Next with regard to outside testimony. What confirmation would it be reasonable to expect?