Drayton’s story sounded plausible, yet Tom was suspicious. He would recommend to the police that they keep an eye on him. As the young inventor was about to leave the infirmary, Dr. Carman called him into the office. Closing the door, he said in a low voice:
“Tom, something our patient mumbled over and over again while he was unconscious might interest you. He kept repeating, ‘Arthur Gray, you were a fool to get caught.’ If this fellow isn’t Drayton, maybe he’s somebody named Arthur Gray.”
“Or the guy who escaped may be Gray!” said Tom.
FOLLOWING A CLUE 25
The more he thought about it, the more Tom became convinced this was the truth. Though the young inventor was eager to get back to his work on the rocket, he felt that the menace to the project should be cleared up first. An idea flashed into his mind and Tom went straight to the boat basin.
“Which speedboat did our visitor take last night?” he asked the attendant. “I want to examine it.”
As the craft was being pointed out to him, Bud joined his friend. “What’s up now, skipper?” he asked, and Tom gave him the latest news.
“See that dark mark along the bow? I believe it’s paint scraped from the seaplane that landed here,” Tom explained.
He bent over and began to whittle it off with a pocketknife, dropping the shavings into an envelope.
“What good is that going to do you?” his puzzled friend asked.
Tom looked up. “It’s sometimes possible to trace a buyer of paint.
Manufacturers have been asked to include some secret invisible chemical in small amounts in their paint so that it can be identified by police if necessary. The FBI gave me the list. Come on over to my lab, Bud, and I’ll test these scrapings.”