again."

"Nothing since then?"

"Not a word."

The major chewed his lip. "Greg?"

"I had a note at Christmas, I think. But what...."

"What did he say in the note?"

"He said Merry Christmas and Happy New Year. Dad isn't much of a letter
writer."

"Nothing at all about what he was doing?"

Greg shook his head. "Look, Major, if there's some sort of trouble...."

"Yes, I'm afraid there's trouble," the major said. He looked up at them,
and spread his hands helplessly. "There isn't any easy way to tell you,
but you've got to know. There's been an accident, out in the Belt."

"Accident?" Greg said.

"A very serious accident. A fuel tank exploded in the scooter your
father was riding back to the _Scavenger_. It must have been very
sudden, and by the time help arrived...." The major broke off, unable to
find words.

For a long moment there was utter silence in the room. Outside, an
elevator was buzzing, and a typewriter clicked monotonously somewhere in
the building.

Then Tom Hunter broke the silence. "Who was it, Major?" he said. "Who
killed Dad? Tell us, or we'll find out!"

2. Jupiter Equilateral

For a moment, Major Briarton just stared at him. Then he was on his
feet, shaking his head as he came around the desk. "Tom, use your head,"
he said. "It's as much of a shock to me as it is to you, but you can't
afford to jump to false conclusions...."

Tom Hunter looked up bitterly. "He's dead, isn't he?"

"Yes, he's dead. He must have died the instant of the explosion...."

"You mean you don't know?"

"I wasn't there at the time it happened, no."

"Then who was?"

* * * * *

Major Briarton spread his hands helplessly. "Nobody was. Your father was
alone. From what we could tell later, he'd left the _Scavenger_ to land
on one of his claims, using the ship's scooter for the landing. He was
on the way back to the _Scavenger_ when the rear tank exploded. There
wasn't enough left of it to tell what went wrong ... but it was an
accident, there was no evidence to suggest anything else."

Tom looked at him. "You really believe that?"

"I can only tell you what we found."

"Well, I don't believe it for a minute," Tom said angrily. "How long
have you and Dad been friends? Twenty years? Twenty-five? Do you really
think Dad would have an accident with a mining rig?"

"I know he was an expert engineer," the major said. "But things can
happen that even an expert can't