A Larger Universe (50 page)

A few minutes later he climbed back onto the bridge.  “Those
blasts are striking where we first emerged behind the nova front.”

Leegh made a chattering whistle.  “They are not accounting
for the nova wind.  If our tests continue to show that we are still here, they
may begin to shoot randomly in this area in hopes of hitting us.”

“We had best hurry, then,” Tommy replied.

#   #   #

When the memory dump from the last test was compared with
the previous dump, significant portions of the code had been bypassed, and new
subroutines had been added with memory addresses greater than anything in the
first dump. 

"Whoever is on the other side of those micro tunnels
tried to modify the program when it responded irrationally," Tommy told
the group.  "We might be years trying to program a Kadiil computer, but if
we understood the patch commands, maybe we could scramble its memory with
garbage."

"Maybe not garbage," Vent said, grinning.  "I
think I've located the shutdown command code."

Tommy joined Vent in front of two stacks of paper. 
"The one on the left is the first memory dump, the other one is the
second," Vent pointed out.  "The address in the first memory register
is different, but each points to a memory location containing the same
operation code.  A code with no modifiers and no memory addresses.  If we
assume the first memory register contains the address of the executing
instruction, that command code is the last thing the Kadiil computer did."

"If you're right,” Tommy said, “we just need to force
the Kadiil computer to overlay two locations in memory, the first register and
an address to contain the shutdown code.  Let's look at the messages going back
and forth through those dimensional tunnels."

Sanos was already working on the messages.  "The false
radio traffic was passed through," he said.  "The Kadiil put some
code before and after each message, and sent it along."

"That should confuse whoever is on the other end,"
laughed Tommy.  "We sent random numbers strung together.  What about
incoming messages?"

"Those are confusing me!" Sanos responded. 
"I got some helpers and we identified several thousand pages of possible
messages.  In the first half of those pages we found the beginning and end of
each message by using the twelve-digit identification number you found." 
He turned to a marked page.  "But from this point on, that's not
true."

"Did you check the first twelve digits after the last
identification number?" Tommy asked.  "Were there repetitions of
those numbers?"

Sanos gave Tommy a blank expression and turned pages. 
"You're right.  Here are the identical twelve digits twice in a row."

"Maybe that's the end of the previous message and the
beginning of the next," Tommy said.  "Does the pattern
continue?"

Sanos flipped more pages, then turned to the last page. 
"Yes.  And the last text ends with the same pattern."

Tommy scratched the back of his head thoughtfully. "I
wonder why they changed the ID code," he mused.

From the other side of the table, Vent said, "I think
you should look at this!  I've matched three examples of code in the messages
to the changed code we found after the second test.  In every case, the changed
code is preceded by a block which includes the address in the memory dump where
I found the changed code."

Tommy walked around the table and looked over Vent’s
shoulder.  After a few minutes, he said, "I think you've found it!  That’s
how whoever is on the other side of those dimensional tunnels makes program
modifications!  We could do the same!"

He paused for a moment.  "There’re flaws in this idea,
though.  It just occurred to me that we must know the ID of the Kadiil ship for
this to work.  And we have no way of knowing if it will process our radio
messages the same way as those it receives from the tunnels.” 

Tommy pulled up a chair and sat down, placing his chin in
his hands.  His gaze focused on the ceiling then back on his guild members. 
“We do know this Kadiil ship's ID, so we can try sending it a radio shutdown
code.”  He stood up.  “Let's try that much, anyway, even if it won't help with
the next Kadiil ship we meet."

#   #   #

Two hours later, everyone except Vent returned to the
hanger.  Tommy waited for a while before deciding to proceed without him since
the test would be brief.  They had disconnected the internal wormholes, and
Tommy’s network would provide the only data the Kadiil computer would receive. 
Five seconds into the simulation, Tommy sent a message, as if by radio,
formatted to change two memory locations and preceded and terminated by the
Kadiil ship's identification code, according to Vent's theory. 

The Kadiil computer shut down.

Vent’s arrival through the airlock interrupted the cheering. 
After Vent had removed his helmet, he said, "Sorry I missed the test, but
I couldn't stop until I was sure.  The messages with the different ID make the
same changes as those in the first half of the messages.  They sent them all
again when they didn't get the response they wanted the first time."

Tommy sat back in his chair.  "Surely, they wouldn't
have done what I'm thinking.  Nobody's security is that bad!"  He put his
hands on his keyboard.  "First, we will run the same test with the
different ID.  If it works, for what I have in mind, we need something a bit
more convoluted."

A few minutes after the Kadiil computer had been started,
they shut it down by transmission of a command with the alternate ID code.

Back in their workroom, Tommy and Vent found what Tommy was
certain was the last piece to the puzzle.  An hour later he had written, and
they both had checked and rechecked, the radio transmission they would be
sending. 
Time to try this live!  If I’m right about the second ID code, it
might be changed at any moment.

#   #   #

He called Cauth, Ulsu, San and Suna to the bridge and
notified Leegh and Whna of his intentions.  He also sent Fen to escort Ull to
the bridge.  Finally, he called Sisle to join them.

Tommy asked Leegh to take the command chair.  "I think
Vent has discovered something important, but our time to use it could be
limited.  And to prove the idea, we must jump away from the nova and wait until
the last possible moment to reenter transit.   If we wait too long--"  He
shrugged his shoulders.

"Why not perform your experiment here?" Leegh
asked.

"The Kadiil ships arriving here are dying from the
nova's effects.  How would we know we were successful?" answered Tommy.

"Why am I here?" Ull asked.

So much has happened since I first met Ull in her
chambers
, he thought, and then responded, "I know this is not what we
bargained for.  You fulfilled your side of the contract, and in return I took
your ship from you.  I will not apologize for that.  You took my life from me
when you stole me from my family.  Perhaps you are here because I feel guilty
about making us the target of the Kadiil.  Maybe you are here because I do not
want you swimming calmly in your pond if the ship is destroyed.”  His ironic
whistle followed by flashing teeth caused Ull to step back into the chests of
her warrior guards.  “Anyway, it seemed like the right thing to do."

When Ull didn't respond, Tommy turned to Leegh.  "Are
you all right with this?"

"If you believe we are ready, I am ready," Leegh
said.

"Transit us to the closest star ahead of the nova wave
front, Tommy commanded.  “I will begin transmitting the message we have
prepared as soon as we exit."

Nine minutes later the dome cleared, and Tommy extended
gravity sensors to three light seconds. 

Tommy watched the sweep second hand of the clock on the
command chair. 

The message transmitted repeatedly.  The first copy was out
to three light seconds, then four, then five. 

The signatures of five incoming wormholes appeared on the
gravity monitor, each closer than ten thousand kilometers. 

They are arriving in force and for the kill!
 

The first Kadiil ship emerged, and then the signature of a
black hole being created overlaid that of the ship on the gravity monitor. 

Leegh stood in front of the command chair, looking
frantically back and forth between the gravity monitor and Tommy. 

“We have to wait!” Tommy said.

Just as the sweep hand passed three seconds from time of
entry, the black hole signature died.

During those three seconds, the other four ships in the
group emerged.  Tommy again watched the sweep hand, and it passed twenty
seconds before he was sure.  All of the Kadiil ships were drifting. 

He looked up to find everyone's eyes on him.

"What did you do?" asked Leegh.

"We took advantage of a security breach."

"A security breach?"

"In the second group of tests, we allowed incoming
communication through the internal dimensional tunnels.  Whoever or whatever is
on the other side of those tunnels tried to take control of the Kadiil
computer, and, when it did not respond, they apparently assumed a computer
failure and tried to rebuild the program that operates the Kadiil ship.  That
is speculation, but that is what it looked like.  They tried twice.  For the
first transmission, they used the Kadiil ship's specific identification.  What
we would call its
user ID
.  When the ship still did not respond, they
tried again, using a different
user ID
.  I decided that ID had to be
what we would call the
superuser ID
.  The
ID
that grants access
to everything.  Vent already understood how to send the shutdown code, but that
was useless without the
ID
of each specific Kadiil ship, which we had no
way of getting.  The
superuser ID
gave us a way around that.  Every
Kadiil ship receiving that
ID
in front of Vent's code was forced to turn
itself off!

"Not surprising, really.  The only way the breach could
be discovered would be to capture a Kadiil ship, and no one had done that for
thousands of years."

In the stunned silence that followed, Sisle asked about
something everyone else had missed.  "I think I follow most of what you
said, but I am confused about one thing.  The first ship emerged from the
dimensional tunnel and had time to begin its attack before its computer
processed your message.  The other ships should have done the same.  Instead,
they were dead when they arrived.  How is that possible?"

Tommy smiled.  "Vent and I also discovered how they
send messages through the internal dimensional tunnels.  We forced the first
Kadiil ship to package the shutdown code as a
superuser
message and send
it through before shutting itself down.  Apparently, the Kadiil ships were
coordinating the attack with each other, and our code disabled the other four
ships before they arrived.

He glanced at the clock on the command chair.  Several
minutes had passed.  "It may be better than that.  Much better.  They are
relentless and have had plenty of time to start a second attack.  We may never
know for sure, but maybe all Kadiil ships are connected through those internal
tunnels.  Maybe those internal dimensional tunnels are their network
connections.   Maybe we sent our
superuser
code over the entire Kadiil
network.  Maybe we shut them all down!"

On three sides stood lofty mountain peaks covered with snow
and the glinting ice of glaciers.  The glaciers fed a rushing mountain river
that in turn became the icy lake that spread out from her feet across the floor
of a wide alluvial valley.  A part of her wanted to join the other adults and
their kits frolicking in the water.

Most of her wanted to kill the feral human standing behind
her who had destroyed her way of life.

She turned to Leegh and Tommy, who stood on the ramp of the
lander.  “You plan to maroon us here.  I can believe that of Tommy,” she spat
out the name, her tail flicking from side to side, “but how can you do this,
Leegh?  You are one of us.”

“Ull,” said Leegh.  “Your ears are filled with water.  We
are not marooning you.”  She waved her arms at the huge pile of supplies around
the base of the lander.  “We are leaving you the means to support yourself on a
water planet like Stream was before our industries polluted its oceans.  You
can build a new civilization here, rather than dying on
The Peoples Hand
.”

“And how will we build a new civilization,” Ull responded,
“without slaves to do the work?  In a single generation, we will be savages.”

“You take innocents as slaves,” Tommy accused.  “As far as
I’m concerned, you already
are
savages.  I’ve given you a chance to
become a great people again.”  Ull offered no answer.  “Anyway,” Tommy added,
“I have pledged to both you and Leegh that we will be back,” Tommy said, “but
with help and as traders, not as slaves.  You will have no more slaves.”

Ull voiced a grinding whistle.  “We had the stars, and you
give us a single world with no one to do the work.  We are marooned, and we
will die here.”

She turned and dived into the lake.  When she surfaced and
looked back, the lander had lifted.  A few moments later, it disappeared into
the crystal blue sky of the world The People had already named
New Stream
.

Before leaving the site of their victories behind the nova
and at the nearby star, they stuffed the hangers of
The Peoples Hand
and
My Flowing Streams
with every drive they had been able to retrieve. 
They kept three of the Kadiil ships intact, except for disconnecting the power
cables.  The remaining ships they stripped down to the drive modules,
discarding the computer boxes overboard.  If all the Kadiil ships were dead,
those drives were literally beyond price.  The transit location of the drives
they couldn't retrieve would remain their closely guarded secret.