“We’re looking for a motor-boat called the Follow Me,” he explained.  “Have you seen her?”

The man shook his head.  “What was she like?” he asked.

Steve described her, aided by Harry Corwin, and the man pushed his old straw hat back, and rubbed his forehead reflectively.  Finally:  “There was a launch answerin’ to that description stopped here about”—­he gazed at the sun—­“about two hours ago, I cal’ate.  She was black, but she didn’t have no name on her so far as I could see.  I sold ’em thirty gallons o’ gas an’ they went on out toward the bar.”

“Who was on her?” asked Steve quickly.

“Two or three men I never seen before.  Three, I cal’ate there was.  She wasn’t here very long.  They come up to the house an’ got me up from the breakfast table.  Said they was in a hurry.  Come to think on it, boys, I believe they’d painted the name out on the stern.  They ain’t stolen her, have they?”

“That’s just what they have done,” answered Steve.  “Shove off, Han!  Thank you, sir.  About two hours ago, you say?”

“Might be a little less than two hours.  Well, I hope you get her.  I didn’t much like the looks of the fellers aboard her.”

“Where do you think they’d take her?” called Joe as the boat swung her stern around.

“I dunno.  They might switch around into the Essex River, or they might take her in Ipswich way, or they might head straight for Newburyport.  If they wanted to hide her I cal’ate they might run in behind Plum Island somewheres.”

“Sounds pretty hopeless,” said Steve as the Adventurer took up her way again.  “Look at this chart and see all the places she might be, will you?  It’s a regular what-do-you-call-it—­labyrinth!”

“It certainly is,” agreed Joe.  “And there’s a lot of shallows about here, too.  Where’s this Plum Island he spoke of?”

Steve pointed it out, a seven-mile stretch of sand behind which emptied four or five small rivers.  “Shall we try it?” he asked.

“Might as well be thorough,” Joe replied.  “What do you say, Harry?”

“I say yes.  Seems to me they’d be mighty likely to slide into some such place if only to paint a new name on.”

“We’ll have a look then,” agreed Steve.  The Adventurer dipped her way across Squam Bar and Steve swung the wheel.  “Southeast, one-fourth south,” he muttered, looking from the chart to compass.  “Watch for a black spar buoy off the lighthouse.  If they took the Follow Me into Essex Bay, though, we’re running right away from her.”

To port, the sand dunes shone dazzlingly in the sunlight and a long stretch of snow-white beach kept pace with them as they made for the entrance to Plum Island Sound.  Several boats, sailing and power craft, had been sighted, but nothing that looked in the least like the Follow Me.  The sun climbed into a hazy blue sky and the day grew hot in spite of the light westerly breeze.  Steve picked up his buoys, a black and then two red, and swung the cruiser in toward the mouth of the Ipswich River.  The chart showed feet instead of fathoms in places and Steve slowed down cautiously until they were in the channel.  They left Ipswich Light on the port beam and kept on past the river mouth and into the sound.