Tom Halstead, ostensibly lounging behind one of the life-boats, saw this move.

"Now, what's he up to?" muttered Tom. "Mischief, judging by his queer antics. We've mischief enough to deal with, without having it take place right on board our own boat!"

Halstead stole forward in time to see Giddings darting down the staircase into the main cabin.

"I'll just get down where I can watch this," muttered Tom. Concealed near the foot of the staircase, he saw Giddings, with some sort of a small tool, prying the lock of Dr. Gray's medicine case open.

"Oho!" muttered Halstead, as he saw young Mr. Giddings abstract a small, screw-capped vial. "There's morphine in that doctor's outfit, and Giddings has guessed it!"

Tossing the medicine case back into the doctor's stateroom, Gaston Giddings stole up the after-companionway to the deck aft.

"With all our other troubles aboard, I don't believe we want any morphine maniacs here!" muttered Tom Halstead, excitedly.

Giddings, quivering with eagerness, trembling with aggravated nervousness, leaned against the stern rail, glancing out over the water as he drew the screw-capped vial from his pocket.

Just as he started to remove the cap from the bottle, a hand shot around him from the rear.

The young skipper of the "Panther" snatched the vial, remarking coolly: