ipred's implication hit Gregor like a ton of bricks. Princess! That could only mean one thing: The rat thought Lizzie was the princess in the prophecy, not Boots, and now he would want to keep her here. "No! No way, Ripred! You can't have her!" He stood up, putting Lizzie on her feet, and then pulled her by the hand toward the door. "Come on, Liz, we've got to get you home."

Ripred planted his big, ratty self in front of the door. "Well, I can't let you go now. It wouldn't be safe."

"This is true," put in Daedalus. "Hermes and your sister were ambushed at the bottom of the shaft that leads to your home. The rats surely have soldiers guarding it now."

"Then she'll go back up through Central Park," said Gregor.

"Even if we had a spare flier at the moment, that wouldn't be advisable. There's probably a patrol posted there as well. And do you really want to drop off poor Lizzie under Central Park alone? How will she move the stone? How will she get home in the dark?" asked Ripred.

Gregor had no idea what time it was, either in the Overland or the Underland. But he couldn't just send Lizzie up to Central Park by herself no matter what time of day it was. He would have to arrange for his dad to meet her. Wait, that wouldn't work. His dad was sick again and, if they couldn't send a bat with a message up the laundry room shaft, how would they even get word to him? There was only one way to get her home. "I'm taking her myself," said Gregor.

"Just try to set one toe outside Regalia and you'll be back in that dungeon so fast you won't know what hit you," said Ripred. "And your bat, as well."

Gregor felt desperation growing inside of him. There was no way Lizzie could manage down here! He had to get her home. But everything Ripred was saying was true. "Why do you even want her? What's this 'princess' stuff? She didn't even get the puzzle right! I know you had shrimp for lunch!"

Ripred rolled his eyes at Lizzie. "You see? This is the sort of thing I've been dealing with for the past year. Enlighten him, won't you?"

"It was just a puzzle, Gregor, not what really happened," said Lizzie. "In the puzzle the rat ate the cheese."

"How did you know that? Did you just guess?" asked Gregor.

"No, it was just the only answer left. He said the mouse didn't eat the cheese. And the two animals who ate mushrooms and cookies weren't mammals, so that means the spider and the cockroach didn't eat the cheese. And cheese wasn't one of the favorite foods of the Overlander, the Underlander, or the bat. So, that only leaves the rat. See?" said Lizzie.

Even her explanation made his head spin. "No, I don't see, Liz," said Gregor. "All I see is I've got to get you home."

"Maybe she doesn't want to go," said Ripred.

"Of course she does!" said Gregor.

"Let's ask her," said Ripred. "Lizzie, if you knew that all the humans in the Underland might die if you didn't help us solve a puzzle, would you stay or go?"

"What?" asked Lizzie, immediately distressed. "Would that happen?"

"Don't tell her that!" said Gregor. "She's not even the princess! Boots is the princess!"

"And if a princess has a sister, you call them a...?" asked Ripred.

"Okay! A princess!" said Gregor. "But that's just some junk the cockroaches made up. Nobody's going around calling me a prince."

"Well, if that's what's bothering you, you'll be Prince Gregor from now on," said Ripred.

"My mom and my sister and my brother, too?" broke in Lizzie, who had not yet answered Ripred's question. "Would they die, too?"

"They may even if you stay. You may, too. Then again, they may live. But if you are the princess in the prophecy and you leave us, none of us stands a chance," said Ripred. "I think everyone in this room would back me up on that."

"IN THE NAMING IS THE CATCHING," said Nerissa suddenly. "That is what the line from 'The Prophecy of Time' must mean. We had a princess, but not the one with the right name. That was the catch. The true princess must be you, Lizzie. You are the one who will help us break the Code of Claw."

"Then I have to stay, Gregor," said Lizzie. "I can't leave and let everybody die."

"What about Dad?" asked Gregor.

"I don't know," said Lizzie. Her breathing began to get short again. "I don't know."

"I'll send money up there. And instructions. Your nice Mrs. Cormaci can hire a nurse, can't she? There are people who do that, right?" said Ripred.

"If you can get a note up there, just have Mrs. Cormaci meet Lizzie in Central Park," said Gregor.

"But I'm not going, Gregor," Lizzie said unhappily. "I have to stay." She turned to Ripred. "How will you get it to Mrs. Cormaci? The rats? The small ones who live up there?"

"Exactly. Such a relief not to have to explain myself all the time," said Ripred.

"I will write the note and have the money collected," said Nerissa. "Then, Ripred, have you need of me?"

Nerissa had turned so white her veins looked purplish-black against her skin. The strain of Lizzie's arrival must have beeri too much for her. Surely she would pass out at any moment.

"No," said Ripred. "Go, see to the nurse, and then rest."

"Yes," Nerissa said, making her way to the door by supporting herself against the wall. "Yes."

"Nerissa, you have been invaluable today," added Ripred, and she acknowledged this with a nod.

Boy, the rat really was in good spirits if he was complimenting Nerissa! If Ripred was happy, Gregor was not. But he knew that arguing with Lizzie at this point was no good. And Ripred had made up his mind to keep her.

A couple of Underlanders came in wheeling carts of steaming food, and Gregor realized how hungry he was. He made a gigantic roast beef sandwich smothered in mushrooms and sat back against the wall to try to figure out another plan while he washed it down with a quart of milk.

Lizzie, whose stomach was also empty, took a slice of buttered bread at Ripred's insistence. "Now come and meet the rest of the code team," said the rat, wrapping his tail around her and guiding her around the room. "I know they all must look very strange to you, but believe me, you've got more in common with them than you do with Prince Gregor over there."

"Why?" asked Lizzie, shooting a nervous look back at Gregor.

"Because you think alike," said Ripred. "Oh, by the way, you don't sing, do you?"

"Not much. I don't like music with words," said Lizzie.

An audible sigh of relief came from around the room.

"Good. Good," said Ripred. Then he leaned and whispered in Lizzie's ear so Gregor could barely hear it. "You'll have to be patient with some of them. They're very shy."

It was the perfect thing to say to Lizzie, who could be almost crippled by shyness herself. She'd always had great difficulty making friends. To be honest, she'd only ever had one friend, a weird kid named Jedidiah. He was in her grade at school and, like Lizzie, way beyond the other kids academically. He was just eight, but he could tell you how anything worked. A car, a telephone, a computer. Once, when he'd come over for a play date, he'd spent, like, an hour talking about their oven. Gregor had finally taken the pair of them out to the playground and tried to get a game of kick-ball going. Lizzie got cold and Jedidiah became fascinated with a traffic light. It was hopeless. Also, Jedidiah always insisted on calling Lizzie by her full name, Elizabeth, and got very upset if you called him Jed or something. Listening to the two of them having a conversation made Gregor feel like he was hanging out with a couple of Pilgrims. "What do you think, Jedidiah?" "I do not know, Elizabeth." Still, the whole family was grateful for Jedidiah. If it weren't for him, Lizzie would have no friends at all.

The fact that the other code-breakers were also shy seemed to give Lizzie courage. She gave them each a polite "hello" as they were introduced. They must have liked her, because they began to come out of their rooms. Daedalus fluttered out almost at once, but bats and humans were most comfortable with one another. Min emerged slowly. She was an old cockroach, so old in fact that she made creaking noises when she walked, and her shell had a funny grayish tint to it. Heronian struggled to her feet, dragged herself up to Lizzie, and gave her a little bow, to which Lizzie gingerly bowed back. And finally, Reflex delicately stepped out, greeted her, and scurried back to his web. Then Ripred took her over to the tree carved on the wall. "This is the Tree of Transmission. It was created years ago to make communication easier over long distances. Humans, rats, mice, spiders, cockroaches, and bats developed it together, which was, in itself, an extraordinary achievement. It was in one of our rare times of peace, you see. We can all still use it today, though. Look at it a moment and tell me your impressions," he said.

Gregor gave the tree a hard look and this is what he saw:

"It looks like a Christmas tree decorated with the alphabet," was Gregor's first thought. But even he could see it must be related to the code.

"I think..." began Lizzie hesitantly.

"Go on, don't worry about being wrong," said Ripred.

"Well, maybe you use these sounds... click, scratch, tap... to make letters," said Lizzie. "One click is an E, one scratch is an A, and one tap is an I. Right?"

"Exactly right," said Ripred. "So what if you heard one scratch and then two taps?"

Lizzie followed the tree branches with her finger as she spoke. "One scratch takes you up to A, the first tap takes you to the right to D, and the second tap takes you to the right to the letter O." Her eyes lit up. "It's sort of like Morse code. The way we use sounds to send messages on a telegraph. With dots and dashes."

"Yes, except Morse code only uses two sounds and we use three sounds. How do you know about Morse code?" asked Ripred.

"My dad showed me," said Lizzie. "Only he didn't have a tree; he had a chart with dashes and dots next to each letter."

"More like this?" asked Ripred, nodding to the floor.

For the first time Gregor noticed the chart carved into the floor. He stood up to get a better view of it.

"Yes, this is like the Morse code chart," said Lizzie. "So, it's just another way of showing the Tree of Transmission."

"Right again," said Ripred. "Some find it to be a helpful learning tool. Of course, the best way to learn it is by hearing it. Scratch-scratch-click. Tap-tap-scratch. Because that's how it's transmitted."

Gregor had been there during the Morse code lesson with his dad, too. It had been somewhat interesting but hadn't stuck much in his brain. Lizzie had been fascinated by it, though, and wanted him to learn it as well so that they could send each other messages. The only thing he could ever decipher was the SOS distress signal that they used on ships and stuff to call for help. Dot-dot-dot-dash-dash-dash-dot-dot-dot. SOS. It was sent as one string with no gaps to even indicate there were three separate letters. SOS. She'd really drilled that one into him. She had played it on the bedroom wall, tapped it out with her fork at dinner, and even used a flashlight to send it with quick flashes for the dots and longer ones for the dashes. Finally Gregor had to cut her off. Lizzie would have had them practicing five hours a day. Like Gregor didn't have enough homework without her assigning him more.

"Well, if you already know how this code thing works, what's the problem?" said Gregor.

"This isn't a code, Gregor. This is just a way to send any message. Like if you picked up a phone and talked into it," said Lizzie. "And anyone could understand what you were saying."

"You've heard it before. Rat claws scratching, tapping, and clicking," said Ripred.

Gregor remembered waking up one night in a cave in the Firelands to such sounds. Ripred had told him to go back to sleep. "Like in the cave," he said.

"Like in the cave. Those messages weren't in code. The rats didn't believe there was any danger in sending them in plain English," said Ripred. "But now, with the war in full swing, everything is in code." The rat pulled one of the strips of white fabric covered in chicken scratch off the table and waved it about. "This code! The Code of Claw! The one in 'The Prophecy of Time'! And this is what we need Lizzie to help us break!"

Gregor finally understood. The clicks, scratches, and taps were not the code. They were as simple as knowing your ABC's. But the messages the rats were sending now made no sense, because they were written in code. An A might be a B or a Q or a V, depending on how the Code of Claw worked.

Lizzie took the strip of fabric and sat down on the ground with it, studying the letters. "Is it like a cryptogram? One letter stands for another letter?"

"Not exactly," said Heronian, settling down by Lizzie. "We would have broken a regular cryptogram in minutes. But there's something else involved."

"There is some trick to make it more complicated. Some sort of substitution," said Daedalus.

"Found it not, have we, found it not," said Min, creaking her way over.

"But the thing is, we haven't much time. Tick, tock, tick, tock," said Ripred, shaking his head in frustration. "Oh, now I'm hungry again." He went over and stuck a whole roast chicken in his mouth.

"Did you get the cookies I helped make?" asked Lizzie, without looking up from the code.

"No, I did not get the cookies you helped make," said Ripred, scowling at Gregor. "Where are my cookies?"

"In my backpack in the hospital probably. I brought them to the battle. Sorry, I just couldn't find the right moment to serve them," said Gregor. "You want me to get them now?"

"I do. I'd better come with you to make sure there are no more mishaps. And I'll make sure the note has gone to your father," said Ripred. He touched Lizzie lightly on the head with the tip of his tail. "Will you be all right here now?"

"What?" said Lizzie, pulling her attention from the letters. "Oh, I think so."

"Good. I'll be back soon," said Ripred.

Gregor stopped at the doorway to double-check that Lizzie wasn't going to become hysterical when they left, but she was discussing some letter sequence with the others. Even Reflex had ventured out to join them. It made a cozy picture, all of them together on the floor. Freakish, but cozy.

Ripred waited until they were out of earshot before he began. His voice — in fact, the whole conversation that followed — was strangely subdued. "Listen, don't fight me on this. Let her stay. We need her to break the code to save people you have come to love."

"I love her, too. She's my sister. And she's real smart but she's not strong," said Gregor. "Not like you have to be to survive down here."

"I know," sighed Ripred. "I know. But Solovet will know she's here by now and have already given orders to prevent her from leaving while the war is on. And after the war, what then?"

"Then it's not a problem. I can take her home myself and —" Gregor came to a standstill as he remembered "The Prophecy of Time."

When the warrior has been killed

He would not be around to take anyone anywhere. "I've got to get Lizzie home now, somehow. And Boots and my mom, too. While I still can," Gregor muttered more to himself than to Ripred.

"You can't. No one can. But if you let her stay now, without a fight, I swear I'll get all three of them home safely after the war," said Ripred.

"No," said Gregor angrily. "What kind of deal is that? If the war's over, there's no reason to keep them here, anyway!"

"Think about it, boy. If we win the war, Solovet will call the shots. Do you really believe she plans to let any of them return?" His voice had dropped to a whisper. "She has told me otherwise. If Solovet has Boots, she has the cockroaches on her side, and if Lizzie is who I think she is... well, she'll be worth her weight in gold as well. No, your father will come to find them and your family will essentially be prisoners down here for the rest of their lives. Unless I help you."

This was a frightening dimension Gregor had never even considered: his whole family condemned to life down here. Once Ripred had said it, Gregor knew it was not only possible, it was likely. "How do I know I can trust you?" asked Gregor.

"I give you my word," said Ripred.

"As a rat?" asked Gregor bitterly.

"As a rager," said Ripred. "As one rager to another. I will get them home."

As Gregor was trying to decide what a rager's word was worth, if anything, the horns began to blow. Ripred cocked his head and listened to the pattern. "The rats have reached the walls to the north. The ones that surround the farmlands."

Gregor could be ordered out there at any moment. He might not come back. Then what?

"What do you say, Gregor the Overlander? Do we have a deal?" asked Ripred.

There was no choice but to trust him. "Yes," said Gregor.

"Good. Now go find yourself some body armor," said Ripred. "I'll see you on the field."