Alex jogged beside Alice, Ellen and Captain Zachary into their fourth room.
It was big enough that their breathing echoed. The floor was the size of a football pitch. The chessboard covered the entire floor up the walls again and the squares were much bigger too. The room was in good condition, with metal walls like the third room, but Alex noticed they were tightly sealed where they met the floor. The ceiling was higher than before with large hatches in it. There were no chess pieces on the board.
"Ah. Invisible Chess, Chata?" said Alice, looking around. "Or Blind Chess? Or reverse Haunted House Chess?"
"No, you'd probably stroll straight through all of those as well," said Chata, from her wall screens, which were also larger than the ones in the other rooms. It let them see her – and the expressions on her face and in her eyes – more clearly than before. "You really are Stephen's grandchildren."
"You did this to him too, didn't you?" said Alex. "You gave him challenges."
The more he thought about it, the more certain he was that Captain Zachary was right. Chata had said in the Billiards Chess room that the momentum dampener was not working. But now he thought about that, he realised he had never heard of a momentum-dampener before.
Chata scowled and her lips twisted.
"Try being alone on this planet for six hundred years," she said. "Try being abandoned by the people who programmed you. Try being alone in your empty shell of a museum with nothing to do and no one to talk to. You'll be thinking up fun things to do on a chessboard when they come back too. It's the only way to keep from going crazy. I'm not entirely sure it's worked, but it's better than nothing."
"I can imagine," said Captain Zachary. He discreetly checked his laser pistol.
"You played these games with King Stephen?" said Ellen.
"Oh, we played games," said Chata. "I gave him the hardest, most fiendish challenges I'd thought of in six centuries. And he... he strolled through all of them like a grandmaster playing a beginner."
"How did he do it?" said Alex.
"He kept changing the rules," said Chata. Her scowl deepened as she remembered. "Not literally. He didn't cheat once. He just... reinterpreted everything. I thought I'd given myself every advantage. But he kept finding ways to use those advantages against me. Whatever game, whatever situation I presented him with, he found a way to turn it around. He kept making arguments that I couldn't argue with. I couldn't find any way to beat him or to stop him leaving. He left his stuff as a consolation prize."
"I see," said Alex. He could guess why Chata had been keen to stop his ancestor from leaving. Meeting one of the greatest chess players in history after six hundred years of being alone must have been a dream come true for her. He remembered from his history lessons that intelligent computers were often close enough to human minds that, just like them, they could imagine and dream. And they could also go insane.
"And now, four hundred years later, here I am in the same situation with his great-grandchildren," said Chata. "So I'm not making the same mistake again. I won't rely solely on processor power. I'm introducing an element of randomness into this next game. I thought I had last time, but this time I really will."
"Don't blame me because you can't play pinball," said Ellen. "And it's not as random as everything thinks it is. You can always guess roughly where each ball is going to go."
"Yes. So you proved," said Chata. "That's way I'm going with something that none of you cannot possibly be good at. Welcome to the Prawns Challenge."
The hatches in the ceiling dropped open. Torrents of water gushed out in thundering waterfalls, at what had to be several hundred gallons a second. The roar of the water filled the room as it spread across the floor. In seconds, it had reached their shoes. The air tasted of salt and Alex realised it was sea water.
"Don't you mean pawns?" said Alice, over the noise.
"No. Prawns," said Chata.
Several matter transmitter lasers flashed on the other side of the room. The beams were longer and wider than they had been before. Several huge creatures materialised. Long thin antenna waved in the air. Huge, many-toothed jaws mashed together. Dozens of legs splashed and huge, lobster-like claws clacked as they thrashed about in the shallow water.
"Holy Supernovas!" said Ellen. She drew her sword as Captain Zachary drew his laser pistol.
"Penaeus monodon," said Chata. "Giant mutated tiger prawns from the Bay of Bengal. You wouldn't believe how much energy it takes to transport them here. The game's very simple, Princess. You can play as any pieces you like and you simply have to win, drown or be eaten."
"How are we meant to win against them!" shouted Ellen, as the prawns noticed them and began slowly crawling towards them, jaws and claws clicking. The water wasn't deep enough for them to move fast, but – Alex felt it flow over the tops of his boots – that was going to change very fast.
"Oh, I'm sure you'll think of something. You've done that every time so far," said Chata.
"Ma'am, we're going to be killed!" shouted Captain Zachary, holding his laser pistol with both hands and trying to work out which part of the prawns to aim for.
"Captain, you're queen's knight!" said Alice, suddenly pushing him forwards. "Ellen, queen's bishop. Alex, King's Bishop."
"Your highness, do we really want to be going forward?" said Captain Zachary, as they waded through the now knee-deep water to their squares. Alice took the queen.
"Yes. Trust me," said Alice, as the eight prawns crawled slowly towards them across the board, getting faster as the water got deeper. "Bishop to Queen's Rook 3."
"Oh, Seven Sisters!" said Ellen, but she ran forwards across the squares. The lead prawn roared and turned and crawled diagonally towards Ellen.
"Alice!" yelled Alex.
He grabbed his sword, his heart rate leaping in terror as the prawn closed on Ellen. Captain Zachary raised his laser pistol and Alex was just about to run straight out of his square and across the board to try to help his sister when the matter transmitter flashed again. The prawn disappeared, halfway to Ellen.
"Thank you, Chata," said Alice, nodding to the screen, where Chata was trembling with rage.
"What?" said Alex.
"Alex, King's Bishop to Queen's Bishop 5," said Alice.
Alex forced himself not to ask. He turned and splashed across the chessboard through the water that was nearly up to his waist. Two prawns turned and crawled towards him, their antenna waving. Alex grabbed his sword hilt again, ready to slash both antenna away if they came anywhere near him, but the laser flashed and both prawns disappeared.
"Oh, ke pyaar ke lie!" shouted Chata, in a language Alex did not recognise.
"Your highness?" said Captain Zachary.
"We're playing chess," said Alice. "You can't make illegal moves. Pawns can only move diagonally when they capture. The matter transporter is automatically set up to remove any piece that makes an illegal move, right, Chata?"
"Yes. Yes, it is," said Chata, through gritted teeth.
"I thought so. That was why you moved the king with the transmitter when we were playing time chess," said Alice. "More randomness can work against you just as much as against us. Queen to Queen's Knight 6."
She quickly dashed across the squares herself. The remaining five prawns all turned and surged in her direction. Alex was almost knocked over by the giant ripples they made in the water, which sloshed against the room's walls. But it stopped seconds later as all five prawns were transported away.
"Very clever, Princess," said Chata, as Alex, Ellen and Captain Zachary waded over to join Alice in the middle of the board. The water was still rising. "However, you forgot one thing."
"What?" said Ellen.
"The game is win, drown or be eaten," said Chata. "Only one of those options is going to open the doors. Now that you've gotten rid of your opponents, you don't have to worry about the last one, but you can't checkmate them to win either. That only leaves the middle one, which should happen in about four minutes."
Alex looked up at the ceiling. The hatches were still open and the water was still pouring in its deafening roar. In the few seconds they had been standing here, it had already risen up past his waist.
"Oh," said Alice. Alex looked across at her and was instantly terrified. For the first time today, his sister looked genuinely worried.
"That's not fair! None of them were playing the king!" shouted Ellen.
"The rules are the rules, Princess," said Chata.
"Oh, Holy Supernovas!"
"Don't worry, your highness," said Captain Zachary. "I've got this."
Alex looked at him in surprise. The captain handed him his sword and laser pistol, then dived into the deepening water and swam in a fast front crawl towards the end of the room. Alex, Alice and Ellen waded after him. By the time they reached the doors, the captain had already pulled a multi-tool out of his pocket, prized open the electronics panel on the door lock and was working inside it.
"That won't work, Captain," said Chata, as Alex and his sisters reached him. "My systems are..."
There was a flash of sparks and the doors started to open.
"Several hundred years old and falling apart, ma'am," said Captain Zachary. "I'm afraid that can also work against you as well as against us."
Chata yelled behind them in Hindi as the water swept them through the opening doors, into the fifth room.
* * * * * * *
In the other fourth room, four of the Sirians – all of them bleeding from several places – had joined Mendoza at the side of the chessboard.
"This is what happens when you practise chess and sword fencing together, Captain," said Lord Blackstar, wiping the blood off the end of his sword with his handkerchief. "You end up thinking of them as two sides of the same coin. They're not. They're two entirely separate disciplines. It's only by focusing completely on one at a time that you can get really good at either. It's why I never went in for Duelling Chess..."
"...Even when the Pleiadean nation team offered you a six-figure salary," said Darla. "We know, Uncle Damon. You're always telling people this story."
"Don't interrupt, Darla," said Lord Blackstar. "Anyway, they haven't heard it."
He was currently standing in the middle of the board. Darla and Will had both moved from their original squares as Lord Blackstar had expertly thwarted all of Mendoza's attempts to flank him. But he had fought all of the duels with the Sirians himself and had not lost – or even been scratched – yet.
"Shut up! Shut up! Shut up!" said Mendoza, wincing as he and the other eliminated Sirians struggled to get quick-heal bandages onto each other's wounds. "You haven't won yet, Blackstar, you infernal Pleiadean demon! I'm changing tactics. Ramirez! Knight to Queen's Knight Seven!"
"Yes, sir!" shouted Ramirez, who was the shortest and most agile looking of the Sirians. He drew his sword and dashed across the board past Lord Blackstar and straight towards Will.
"You may be skilled, Blackstar," said Mendoza, "but is your assistant?"
"Will, he favours his right hand and keeps his weight on his left foot," said Lord Blackstar, glancing at Ramirez's build and posture as he ran past him.
"Yes, sir," said Will, stepping into his own fencing stance and raising his sword as Ramirez ran onto his square and instantly launched his attack. Their swords rang out and the blades flashed as they thrust, slashed and parried.
"You won't win, Pleiadean," said Ramirez, through the flashing blades. "You're not as good as him."
"Not yet. Maybe never," panted Will. "But he's my teacher."
He parried Ramirez's latest stroke and dropped down to one knee as Ramirez's counter attack swung over his head. Before Ramirez could bring his sword back, Will swung his upwards and neatly jabbed the Sirian under his arm.
"Aaahh!"
"Bishop captures Knight," said Will, standing up and landing his sword against the side of Ramirez's neck.
"Curse it!" yelled Mendoza, from the side of the board.
"Queen to King 5. Well done, Will. Not bad," said Lord Blackstar, as Ramirez was teleported away. "But you didn't need to use eleven moves. You could have done it in six."
"Sorry, sir," said Will.
"Not yet, but you will be!" said Mendoza. "He's not your only weakness! Ortega! Rook to Queen Five!"
"Yes, Captain," said Ortega, in a deep, rumbling voice. He was the tallest of the Sirians, nearly seven feet, and the most muscular, with a completely shaven head, long arms and even longer scars on his face. Like Lord Blackstar, he carried an extra-long sword, which he drew slowly as he walked calmly across the board, between Lord Blackstar and Will, towards Darla.
"What? Wait. No," said Lord Blackstar. He started to move, but then froze as the tip of his shoe touched the energy field at the edge of his square, making it ripple.
"That's right, Lord Blackstar," said Chata, who had been grinding her teeth in silence while Lord Blackstar had worked his way through the Sirians. Now she looked cheerful again. "Make an illegal move and you're out. Your niece can run if she wants to, but otherwise, she's on her own."
"Oh, good grief! My lady!" said Will.
Darla, who had not taken a single fencing lesson in years, had gone pale. She backed away to the edge of her square, as Ortega marched into it.
"Darla, I...," said Lord Blackstar, trying to think of some advice that would actually help. "I..."
"I'm... afraid I didn't bring a sword," said Darla. She tried to sound calm, but she was not able to hide tremor in her voice or the one in her knees.
"Not a problem, señorita," said Ortega, holding out his hand. "Ibanez!"
Ibanez – the third man Lord Blackstar had defeated – stepped to the side of the chessboard, wincing slightly from his injuries, and threw his sword across the board. Ortega caught it by the hilt, flipped it around and caught again it by the blade and bowed formally as he offered it to Darla.
"Señorita."
"My lady, just run!" called Will.
"Yes! Darla, go!" yelled Lord Blackstar. "Forget the notebook! We'll..."
"Thank you, señor," said Darla, as she stepped forward, took hold of the sword, and then kicked Ortega hard between his legs. Ortega collapsed onto his knees, doubled over and gasping, as Darla stepped back, drew her laser pistol and shot him neatly in the forehead with a green laser bolt that was designed to cause unconsciousness.
"Knight captures Bishop whatever," said Darla, as Ortega slumped out cold on the chessboard. She looked around and smiled at Lord Blackstar, Will and the other Sirians, who were all staring at her with open-mouthed horror.
"Darla!" said Lord Blackstar.
"Don't worry, Uncle Damon. I can remember my own name," said Darla, sliding her laser pistol back into its holster and stepping over Ortega.
"That is not...! That was completely dishonourable!" said Lord Blackstar.
"Yes, it was!" shouted Mendoza. "I demand a rematch!"
"My lady, how could you?" said Will.
"What? I won, didn't I?" said Darla. "And that was only two moves."
"Oh, Seven Sisters! I don't believe this," said Lord Blackstar, pressing his fist against his forehead. "You can never tell anyone about this, Darla. I'm serious. No one. The family name. Our reputation would be ruined..."
"Oh, it's going to be!" said Mendoza. "We will tell everyone we meet how famous Damon Blackstar..."
"...Beat your entire team singlehanded in less than five moves each?" said Darla. "Go right ahead."
"Wha...? Yes," said Lord Blackstar, quickly looking around. "And despite the circumstances, this is still undoubtedly checkmate. Open the doors, please, computer. It's been nice knowing you, Captain, and you won't have to worry about running out of explosives now. I'm sure she'll transport you right back to the start."
"Actually, they're not going anywhere," said Chata.
The transmitter laser flashed again. It moved upover all of them as they were transported to the next room.