“Sailing bluebirds, and slices of pickled onion!” cried John Tallman, exploding into one of his characteristic odd remarks. “You can hardly see him for spray!”

“And gray is an odd color for a yacht!” commented Stanley, pushing his mop of sandy hair back from his eyes, the better to study the form and speed of the racing boat which was now sweeping across the bows of the smoothly sailing sloop.

The Water Witch pitched and tossed in a moment or two as the wide “V” of the speedboat’s wake crossed the course of the sailboat. The rigging and sails of the black-hulled boat slatted and swayed drunkenly, then she steadied in the strong southwest breeze sweeping up the bay and continued her easy dip and roll through the waves of the open bay. The speedboat sped off towards the islands, almost silently, save for a low humming.

“More than one thing odd about that boat, John!” Stan remarked. “Extra speed, gray paint, and an underwater exhaust! If this were prohibition times I’d say—rum-runner!”

“Me too. Dunk me in the briny deep and hang me up to dry! Slide over the hamburgers, mates, but I’ve a hunch we haven’t seen the last of that craft!”

“Funny, John,” the G-man’s son said, half aloud, half to himself, “I’m thinking the same thing.”

John Tallman shrugged his shoulders, then laughed as cheerfully as he could.

“Trouble with us, Stan,” he said, “is that we’ve seen so much of speeding boats and water fights that we just jump to conclusions! Because we just spent the last week or so helping capture Dapper Dan Hogan and his gang and those other mobsters, we’ve got detecting and suspicion on the brain! Bluebottle flies and anthill creepers—let’s drop the subject! Me for coffee and doughnuts!”

“Attaboy, John,” laughed Stan. “Stir up some eats. We ought to be close to Porpoise Island by sunset!”

John watched the last white spray of the speedboat disappearing towards that very spot of the barely visible humps of the Off Shore Islands, a perplexed frown upon his lean features, then he ducked down into the cozy cabin of the sloop to dig up a snack of food for the famished boys, for they had been under way for hours now and were very hungry.