"A visitor?" Tom looked at his father.

"From another planet," Mr. Swift revealed.

Both boys were amazed and excited. "Wow!" Bud gasped. "Male or female? Human or animal?"

Mr. Swift's eyes twinkled. "None of those," he replied as the boys stared, mystified.

[CHAPTER II]

THE MYSTERIOUS HITCHHIKER

Tom and Bud were bursting with curiosity. Although the Swifts had been in radio contact with creatures from outer space for many months, this was the most exciting news yet!

On one occasion, the unknown beings had moved a small asteroid—the phantom satellite Nestria—into orbit about the earth. Later they had sent strange samples of the animal life of their planet, aboard orbiting missiles, to be studied by the Swifts. They had also helped Tom, Bud, and Mr. Swift a number of times when their lives were at stake while on daring voyages beyond the earth. What was their latest intention?

The telephone rang and Sandy went to answer it.