When Strong discovered that Coxine had outwitted him, he had gone aboard
the rocket cruiser _Arcturus_ of Squadron Ten and had continued on
search patrol. He dared not break audio silence to warn the cadets
aboard the _Polaris_, lest he give away the position of the ship. Later,
when the radar officer of the _Arcturus_ reported a steady signal over
the audioceiver, Strong at first dismissed it as some form of
interference from space. But when Titan failed to report the arrival of
the _Polaris_ on time, Strong investigated the strange sound. Taking a
bearing on the signal, he discovered it came from a position dangerously
close to the small Jovian colony of Ganymede. After repeated attempts to
raise the _Polaris_ failed, and no distress signals had been received,
Strong feared that Bull Coxine had won again. In a desperate effort to
catch the criminal, he took repeated bearings on the signal and ordered
full emergency space speed toward the small satellite of Jupiter.

Contacting Commander Walters at Space Academy, Strong related his
suspicions and received permission to carry out a plan of action.

"I want you to engage the enemy at all costs!" ordered Walters. "Blast
his space-crawling hide into protons! That's an order!"

"Yes, sir!" replied Strong with grim determination. "There's nothing I'd
like better."

Six hours later Strong received confirmation of his worst fears. He was
handed a message that read:

EMERGENCY:

GANYMEDE GARRISON ATTACKED ZERO THREE HUNDRED HOURS BY TWO SHIPS.
ONE VESSEL IDENTIFIED AS ROCKET CRUISER POLARIS. SEND AID
IMMEDIATELY. ENTIRE COLONY AT MERCY OF COXINE. SIGNED, SOMMERS,
MAJOR, SOLAR GUARD.

Strong realized at once that the cadets had been forced to give the
recognition code to the pirate. There wasn't any other way for the
pirate to penetrate the defenses of Ganymede. And, thought Strong
bitterly, to blast Coxine was to blast the cadets as well. The
commander's words echoed again in his ears, "... blast him, Steve!
That's an order!"

Strong turned to his second-in-command. "Man all guns! Stand by to
attack under plan S! We'll engage the enemy as soon as he's sighted!"

The young officer saluted and turned away quickly. But not before he saw
the mist in Steve Strong's eyes.

* * * * *

Tom, Roger, and Astro watched the incredible scene taking place in front
of them with unbelieving eyes. Seven men were standing at ri