To a person looking up from the earth, the situation would have appeared to be simple—­a matter of three planes zooming homeward after a long practice flight.  The five-pointed star in the black circle, painted on each wing Of the government planes, would probably have been invisible at that height, and the bold lettering of THE THUNDER BIRD indistinguishable also on the shadowed underside of the outlaw plane.  To the government planes she was branded irrevocably as they looked down upon her from their superior height.  There was no mistaking her, no hope whatever that the scouts might think her anything but the outlaw plane she was, flying in the face of international law, trafficking in treason, fair game if she once crossed the line.

On she went, boring through the night, heading straight for Tia Juana, which lies just south of the line.  Just north of that invisible line her pursuers held doggedly to the course.

“Turn back,” Cliff turned to shout to Johnny who was driving big-eyed, his lips pursed with the tense purpose that held him to his work.  “Turn back and land at the rancho.  We’ll never make Los Angeles with those damned buzzards after us.  I’ll have to notify Sch—­somebody.”

“Send him a thought message, then.”

“Turn back when I tell you!” Cliff twisted around as far as his safety belt would permit, that he might glare at Johnny.  His tone was the long of stern authority.

“Can’t be done!  The Thunder Bird’s took the bit in her teeth.  I’m just riding’ and whippin’ down both sides!” Johnny laughed aloud, Cliff’s tone releasing within him a sudden, reckless mood that gloried in the sport of the chase and forgot for a moment its grim meaning.  “Whoo-ee!  Go to it, old girl!  They gotta go some to put salt on your tail—­whoo-ee!”

“Are you crazy, man?  Those are government planes!  They’re probably armed.  They’ll get us wherever we cross the line—­turn back, I tell you!  You’re under orders from me, and you’ll fly where I tell you!  This is no child’s play, you fool.  If they get me with what papers—­it’ll be a firing squad for you if they catch you—­don’t forget that!  Damn you, don’t you realize—­”

“Sit down!” roared Johnny.  “And shut up!”

“I won’t shut up!” Cliff’s eyes, as Johnny saw them facing the moon, looked rather wild.  “You’re working for me, and I order you to take me back to Schwab’s.  You better obey—­it will go as hard with you as it will with me if those planes get in their work.  Why, you fool, they—­”

“What the heck do I care about them?  I’m working for a bigger man than you are right now.  Sit down!”

“Stop at Tia Juana then and let me out.  But I warn you—­”

“Shut up!”

“I will not!  You’ll do as I tell you, or I’ll—­”

“Now will you shut up?” Johnny swung his gun, a heavy, forty-four caliber Colt, of the type beloved of the West.  Its barrel came down fairly on the top of Cliff’s leathern helmet and all but cracked his skull.  Cliff shut up suddenly and completely, sliding limply down into his seat.