poor head I kinder guess I'd a'slipped up right then an' there an'
give the hull scheme away which would a'been a danged shame, an' busted
the game higher'n a kite."

"We make a pretty good team, matey," said Jack. "Sometimes it's you that
goes loco, and threatens to step off your base, and then another time I
feel myself side-slipping and have to lean on you to hold my own. That's
just how it should be with partners--give and take, with never a bleat
if our calculations go wrong."

"It's right nice o' you to talk that way, brother," Perk hastened to
assert, beaming with pride and making out as if tempted to begin
scratching again when Jack reaching around, gently steered his clutching
fingers away from the itching locality, at which Perk heaved a relieved
sigh and nodded his thanks.

"The sky has lost most of that glorious color," mentioned the head
pilot, "and before long now we can be hopping-off. Our first job will be
to swing down the coast and learn if there seems to be anything going on
among the southern islands in this beastly mangrove section where a man
could easy enough lose himself for keeps among the countless water
passages and inlets. See here, what's the matter with you, staring that
way, Perk?"

"Wouldn't that jar you now," snapped the other, "that Robin ship is
headin' back this way; or else some other crate that looks like its
twin!"

[Footnote 1: See "_The Sky Detectives_; or _How Jack Ralston Got
His Man_."]

CHAPTER II

THE CURTISS-ROBIN PLANE

Jack, a bit startled by his companion's sudden exclamation, took a good
look and hastened to remark:

"Reckon now you hit the nail on the head that time, Perk and it's
heading this way in the bargain. Why d'ye suppose we didn't see the
crate before?"

"Huh! I kinder guess now," Perk went on to say, "she bust out o' that
little fog cloud right to the south--a'swoopin' up the coast, you
notice, partner, don't you?"

"Sure is," assented Jack, as though that small circumstance assumed some
importance in his eyes, as well as those of his comrade.

"Ginger pop! but mebee I ain't glad we didn't show any hurry to kick off
this camouflage green stuff, thinkin' it'd served its purpose okay and
could be knocked into the discard. See how they keep dodging' in an' out
like they might be scourin' every foot o' shore line, little bays back
o' these mangrove islands an' all. Strikes me they're a'searchin' for
somethin', Jack, which might be the pai