They were halfway out on the reef when the plane leveled out of its dive with an earsplitting whine.

“Hide!” Tom shouted, fearing a bomb might be dropped.

  [Illustration
   (Tom and friends are attacked by a ray gun from an airplane)]

All leaped for cover among the rocks.  At the same instant, a fiery beam like a bolt of lightning shot from the plane.  It seared the spot on the reef they had just vacated!

“A ray gun!” Bud gasped.

The plane’s speed had already carried it far past the island.  Before it could maneuver around for another pass, Tom and his companions were on their feet, racing for the safety of the Sea Hound.

They were aboard and clamping shut the hatch lid as the jet made its second pass.  This time its fiery ray glanced harmlessly off the seacopter’s Tomasite sheathing.  Seconds later, the Sea Hound had darted off beyond reach into the ocean waters.

“Whew!  We really broke all speed records that time!” Arv panted.

The others looked at him with wan but triumphant grins.  Then they began to speculate on what the beamlike bolt was, who was in the plane, and if their enemy knew who Tom’s group were.

Dawn was streaking the sky when the seacopter arrived at Fearing Island.  The adventurers flew back to Enterprises at once.  Tom and Bud snatched a few hours’ sleep in the apartment adjoining Tom’s laboratory.

Later in the morning the whole group gathered in Tom’s laboratory to recount the raid to Mr. Swift and Harlan Ames.  A bell signal from the electronic brain brought them rushing to the decoder.  Grim news awaited them.  The message said: 

    EXMAN TO SWIFTS.  YOUR ENEMIES ARE NOW SURE I AM SPY.  THEY PLAN
    TO DESTROY ME.

“No!  It mustn’t happen!” Tom cried in dismay.  “Dad, I’ll rescue him myself!”

His words were greeted with shocked protests from the others.

“Don’t be crazy!” Bud said.  “You wouldn’t have a chance!”

“It would be suicide!” Arv Hanson declared.

Chow grabbed his young boss by the arm.  “Brand my cayenne pepper, before I’d let you make a blame fool move like that, I’d rope an’ hawg-tie you myself!”

Ames interjected the most convincing argument.  “I know how you feel, Tom,” he said sympathetically, “but I’m positive the United States government would never permit such a risky undertaking.”

Tom was beside himself with anxiety.  Not only had he worked and struggled to make the space brain’s visit a scientific success, but also it was he who had thought of the scheme to use Exman as a spy.  In Tom’s eyes, if the Brungarian rebels were to destroy the brain’s body, it would amount to murder!  The young inventor knew that the destruction of the “body” would not destroy the energy, but that it would be “lost” as far as the earth was concerned.

Who knew, Tom asked himself, what priceless secrets the “brain” might ultimately yield to earth’s scientific researchers?  If the Brungarians were to succeed, this might deter the Swifts’ space friends from ever attempting another visit to our planet!