at once."

His own intercom hummed, and a voice came on. "Dr. Chi Tung is not in
the morgue. He left with Mr. Blackhawk some time ago."

The captain frowned, but pushed the engineering room intercom. "Is Dr.
Chi with you, Mr. Blackhawk?" he asked, and when Mike's voice
answered, "Yes, sir," he said, "Will you both report to the bridge at
once, please?"

When the two arrived, only a little tardily, on the bridge, the
captain addressed Ishie.

"You heard of the disaster last night?" The physicist nodded. "We
assumed then," the captain told him, "that a meteor had caused the
disturbance. That it had gone through the balloon making a hole
through which the balloon's nitrogen was escaping, making a jet action
and accelerating the ship.

"It seems, however, that we are under acceleration, and that the
acceleration is too great to be such jet action, since Hot Rod does
not have sufficient pressure.

"The computer reports that the acceleration is derived from an
external magneto-ionic effect. Would such an effect be a result of a
flare?" he asked.

"I believe it could, captain. I should have to do a bit of math,
but...."

"We will assume, then, that the computer is correct," the captain told
him. "Could such an effect have a sufficiently great effect on this
ship to give it as much as six hundred forty pounds of thrust?"

"Again, I should have to check the math, captain, but I would assume
so."

"Mr. Blackhawk," the captain turned to his engineer, "could such a
thrust throw Hot Rod off her communications beam and cause last
night's disaster?"

"I guess I'd have to check by math, too, captain...." Mike appeared to
debate the question. "It would be a very small acceleration at first,
of course," he said, "from six hundred forty pounds of thrust. But Hot
Rod's cable is slack, and the velocity needn't be great to give it
quite a jolt when the slack was taken up. Yes, I feel sure that could
happen, captain."

[Illustration]

The captain relaxed a little, and a half-smile played near the corner
of his mouth as he said to Mike, "I believe, then, we may have found
the _real_ saboteur, Mr. Blackhawk." Then to Ishie. "Doctor, I believe
that your field is the one in which the most experience lies towards
finding a means for counteracting the effect that is now influencing
our orbit. I am putting you in charge of the problem. The pull,
according to the computer, is as I said, six hundred forty pounds. Do
you think you