"When you do, you'll find me ready," Whitney answered. "But we'll get back to business. Which way do you suppose he's gone?"
"On the whole, I think south toward Dalbeattie; it's nearer the Solway. As it might be better to follow the road he'd take, we'll have to run back nearly to Dumfries."
"That's all right," said Whitney. "Get in. She seems to be feeling particularly good to-day, and I'm going to let her hum."
They raced back eastward while the distant hills turned gray in front of them. Then they turned sharply to the south, and soon the road skirted a railway line. Whitney got down when they reached a station.
"Have you seen a small, black motorcycle?" he asked a lounging porter.
"Yes; I mind her because I thought she was running verra hard for a wee machine. If yon man's a friend o' yours, ye'll no' catch him easy."
"When did he pass?"
"It would be about five minutes after the Stranraer goods cam' through, and that's an hour ago."
Whitney ran back to his machine and jumped into the saddle.
"We're on his trail, but he must have come straight and fast from Dumfries. Well, we'll get after him."