Tom and slammed his fist on the chair-arm. "By
the ten moons of Saturn...." he exploded, and then he was on his feet,
shouting at the startled Map Control officer. "Get me Martinson down
here, and fast. Call the port on a scrambled line and tell them to stand
by with a ship on emergency call, with a crack interceptor pilot ready
to go. Then get me the plotted orbits of every eccentric asteroid that's
crossed Mars' orbit in the last two months. And double-A security on
everything ... we don't want to let Tawney get wind of this...."

Later, while they waited, they went over it to make sure that nothing
was missing. "No wonder we couldn't spot it," the Major said. "We were
looking for an asteroid in a standard orbit in the Belt."

"But there wasn't any," Tom said. "Dad's rock was isolated, nowhere near
any others. And we were so busy thinking of the thousands of rocks in
normal orbits between Mars and Jupiter that we forgot that there are a
few eccentric ones that just don't travel that way."

"Like this one." The Major stared at the screen. "A long, intersecting
orbit. It must swing out almost to Jupiter's orbit at one end, and come
clear in to intersect Earth's orbit at the other end...."

"Which means that it cuts right through the Asteroid Belt and on out
again." Tom grinned. "Dad must have seen it coming ... must have thought
it was on collision course for a while. But he also must have realized
that if he could hide something on its surface as it came near, it would
be carried clear out of the Belt altogether in a few days' time."

"And if we can follow it up and intercept it...." The Major was on his
feet, talking rapidly into the telephone. Sleep was forgotten now,
nothing mattered but pinpointing a tiny bit of rock speeding through
space. Within an hour the asteroid had been identified, its eccentric
orbit plotted. The coordinates were taped into the computers of the
waiting Patrol ship, as the preparations for launching were made.

It could not be coincidence. Somewhere on the surface of that tiny
planetoid racing in toward the Sun they knew they would find Roger
Hunter's secret.

* * * * *

Below them, as they watched, the jagged surface of the asteroid drew
closer.

It was not round ... it was far too tiny a bit of cosmic debris to have
sufficient gravity to crush down rocks and round off ragged corners. It
was roughly oblong in shape, and one side was sheer smooth rock