“I told Cardona why,” replied Cranston. “It was just a guess. It really didn’t matter which way the cab was headed. It happens though that there were two cabs, not just one.”
Margo’s slow nod meant that she understood more or less, so Cranston decided she should understand more.
“Two identical cabs,” Cranston explained, “even to a duplication of the license plates. The idea was to establish an alibi for both.”
“For both?”
“Of course. One was checked at the west entrance to the transverse while its driver was faking a flat tire. The time element proved that it couldn’t be the cab that took Ames from the hotel. However, that cab never completed its trip through the transverse. It swung into the old stable, was hoisted in the elevator, and went its way along the upper drive.”
“And the other cab came out below!”
“Correct. It was the cab that abducted Ames. Its driver completed the alibi that the first man had begun. His cab was brought down by the elevator to continue through the transverse.”
“Then that’s why the driver reported to the officer at the east exit!” exclaimed Margo. “He wanted to be recognized later, if necessary!”
Cranston nodded. Then:
“Above all,” he added, “the purpose was to draw all suspicion from Central Park, the place where a lot has happened and a lot more will. Well, Margo” - Cranston was glancing at his watch - “I’ll need what’s left of the afternoon. I’m going down to the Graceland Memorial Library.”