"Someone got the log-on of the head of security?" said Father.
"Humiliating, you may be sure," said Graff.
"You've fired him?" asked Mother.
"That would not make us more secure, to lose the man who is our best defense against whatever operation that message triggered."
"So you think it is the English word 'on' and it means somebody is preparing to move against us."
"I think that's not unlikely. I think the message was sent in the clear. It's only undecipherable because we don't know what is 'on.'"
"And you've taken into account," said Mother, "the possibility that Uphanad actually sent this message himself, and is using the fact that he told you about it as cover for the fact that he's the perpetrator."
Graff looked at her a long time, blinked, and then smiled. "I was telling myself, 'suspect everybody,' but now I know what a truly suspicious person is."
Peter hadn't thought of it either. But now it made perfect sense.
"Still, let's not leap to conclusions, either," said Graff. "The real sender of the message might have used Major Uphanad's sign-on precisely so that the chief of security would be our prime suspect."
"How long ago did he find this message?" asked Father.
"A couple of days," said Graff. "I was already scheduled to come, so I stuck to my schedule."
"No warnings?"
"No," said Graff. "Any departure from routine would let the sender know his signal was discovered and perhaps interpreted. It would lead him to change his plans."
"So what do we do?" asked Peter.
"First," said Graff, "I apologize for thinking you'd be perfectly safe here. Apparently Achilles's reach--or perhaps China's--is longer than we thought."
"So do we go home?" asked Father.
"Second," said Graff, "we can't do anything that would play into their hands. Going home right now, before the threat can be identified and neutralized, would expose you to greater danger. Our betrayer could give another signal that would tell them when and where you were going to arrive on Earth. What your trajectory of descent is going to be. That sort of thing."
"Who would risk killing the Hegemon by downing a shuttle?" said Peter. "The world would be outraged, even the people who'd be happy to see me dead."
"Anything we do that changes our pattern would let the traitor know his signal was intercepted. It might rush the project, whatever it is, before we're ready. No, I'm sorry to say this, but...our best course of action is to wait."
"And what if we disagree?" said Peter.
"Then I'll send you home on the shuttle of your choosing, and pray for you all the way down."
"You'd let us go?"
"You're my guest," said Graff. "Not my prisoner."
"Then let's test it," said Peter. "We're leaving on the next shuttle. The one that brought you--when it goes back, we'll be on it."
"Too soon," said Graff. "We have no time to prepare."
"And neither does he. I suggest," said Peter, "that you go to Uphanad and make sure he knows that he has to put a complete blanket of secrecy on our imminent departure. He's not even to tell Dimak."
"But if he's the one," said Mother, "then--"
"Then he can't send a signal," said Peter. "Unless he can find a way to let the information slip out and become public knowledge on the station. That's why it's vital, Minister Graff, that you remain with him at all times after you tell him. So if it's him, he can't send the signal."
"But it's probably not him," said Graff, "and now you've let everybody know."