Disclaimer: One: I don't own X-Men, Thundercats, Jackie Chan, or characters from Jackie Chan Adventures. Second: This was written mostly by me, along with Myra Kat, from a yahoo group.

The Stone of Immortality

My name is Ororo Munroe, also called Storm. I am one of the X-Men. Who are the X-Men, you ask? We are a group of mutants that fight for the good of humans-and mutants. Our leader is Professor Charles Xavier. But lately, we have seen more mutations happening to us. Changes that are too unreal. To me, Cyclops, even Professor Xavier. We don't know what's going on. Let me tell you how it all started.

"Hey, Cyclops!" Beast yelled from the bottom of the stairs.

"What, man?"

"Have you seen my super deep ice freeze degenerater?"

"What in the world are you talking about, Beast?" Cyclops said, now at the top of the stairs in a T-shirt & a pair of underwear. "I have no idea what you just said or what it is. Ask Wolverine."

"Already did. He told me to ask you."

"Is there a problem, you two?" Professor Xavier asked. He had just showed up in his hovercar.

"Yes, I can't find my super deep ice freeze degenerater," Beast replied irritably. "And Scott isn't helping much."

"Did you check your bedroom? I think you put it there yesterday."

"Okay. Thanks, professor."

Later that day, Professor Xavier got a phone call from an old friend, John Chan, an archeologist.

"Charles, Jackie and I need you and the X-Men to come to Egypt right away. We've found a tomb that is very strange," John said.

"Strange? How, John?" Xavier asked.

"Well, all of the workmen who went in never came out the way they were. They came out almost…cat-like. It's a puzzle to me."

"We'll be down as soon as we all get ready. See you, John." With that, Professor Xavier hung up the phone.

In a few hours, all the X-Men were packed and ready to go. They put their luggage in the X-Jet and took of for the city of Thebes, Egypt. As they traveled, the professor filled the X-Men on what John Chan said.

"Professor, what you're saying is that someone or something in that tomb is creating cross-species mutations in the excavation workers for the project," Jean Gray said with interest.

"Yes, and what puzzles me most is that it affected everyone except John and his brother Jackie. Somehow they have developed a block against it, whatever is causing these changes."

"So, what John wants us to do is to help him and Jackie in the excavation of the tomb as well as figure out what is causing the changes," Rouge mused.

"Yes, but I'm not sure how he wants us to help. He didn't exactly say over the phone," Xavier replied in answer to her question.

A few minutes later, they landed in the city of Thebes. John Chan was there to meet them. Professor Xavier introduced all the X-Men to John. As they were going to the excavation site, John filled the X-Men on what was going on.

"It's strange. We don't know what is going on. We want you to help us figure out the problem w/out making it seem too suspicious."

"So what you and Jackie want us to do is to help you figure out what's going on while pretending to be an excavation crew?" Storm asked.

"Yes. That will both be easy and difficult. You guys know the easy part. The hard part is that the Egyptian government didn't really want me to continue this dig after what happened to the original crew." John explained worriedly. "Jackie is on the phone with them now trying to explain what we want to do."

The X-Men agreed to help him in this mystery. As they reached the camp, Jackie Chan ran out to meet them.

"Hello, Charles, Scott, Logan, Jean, Ororo, Rouge, Gambit, Dr. McCoy, Jubilee, Kitty, Kurt. Thank goodness you all are here. The Egyptian government changed their minds and was about to close down the excavation unless we found another excavation crew," Jackie said worriedly.

"Now you have one, sugah," replied Rouge.

"When can we start?" Jubilee asked.

"As soon as we all get ready, Jubilee. Be patient," Jackie said, nearly laughing at the excitement.

"I can tell that you guys can't wait to get started," John remarked.

"John, Jackie, we just want to help in any way we can," Cyclops reminded the brothers.

The X-Men unpacked their clothes, got changed, and met the Chan brothers in front of the tomb. They all took a helmet & put it on just in case rocks fell on their heads. They walked in the tunnel leading down to the king's chamber. On the way down, John was giving them a tour.

"Practically all of the doors have been opened except for one. We've opened it countless times before, but it keeps resealing itself. We've mentioned it to Uncle, and he started to research it."

"Typical Uncle, I tell you," Jackie said.

"Weird. Why would a door keep resealing itself?" Wolverine asked.

"Maybe it's like you, Logan," Cyclops replied, with sarcasm in his
voice.

"Very funny, Scott. I otta kick you one for the score," was the reply.

"I wasn't trying to be funny."

"Sure sounded like it."

"Wasn't meant to be."

"Do you think this place is cursed, Jackie?" Jubilee inquired, to change the subject.

"Not that I know of, Jubilee. We've translated all of the hieroglyphics, but none of them mention a curse."

"How about the ones over here, by the door?" Rouge requested, pointing out a group of hieroglyphics.

"I don't know, Rouge. I've never seen these before," John replied.

"We must have been here 100 times and never noticed them," added Jackie.

"It looks like it definitely mentions a curse," Jean Grey said, "but then, I'm no expert on hieroglyphics."

"Jean, you could be right. This definitely looks like a curse," Jackie mused.

"Well, curse or no curse, we've got to solve this mystery," urged Professor Xavier.

They all agreed on that. The door was reopened and they went inside. Almost immediately, they all heard the sound of a dog barking at them and a voice telling the dog to be quiet. Curious, they followed the sound.

What they saw next surprised the X-Men. There were four skyscraper-sized statues of animals, including a croc. In the middle of the room was a huge, circular thing that could have been a pool, but it somehow didn't look it. They didn't know what to make of it. At the far end stood a closed coffin and no sign of a dog.

"I don't like the looks of this place. It gives me the creeps, goosebumps, shivers, freaks, or whatever you want to call it. It's scary."

"I agree with you there, Ororo. It is scary, almost enough to give you nightmares," Scott said.

"I'm going to have nightmares!" Jean said. By the look on her face, which was white like she'd seen a ghost, was enough said for everyone else.

"Don't worry about it, Jean. It'll all be okay," Jackie said, reassuringly. He added, "The first time I came in here, I thought I was going to have nightmares."

"Thanks, Jackie," Jean replied, relieved.

As they began to explore the place, they came across a group of things that looked like prison cells. In each of them, there was a figure that looked kinda like a cat with two legs. Each of them was asleep at the moment.

"Look! In the last cell, there are two of these strange beings," Storm half-whispered.

"Keep your voice down, Ro. They might hear us and wake up." Cyclops warned.

"Too late." One of them, the one that looked like a cheetah, awoke with a start.

"Who are you guys & what are you doing here?" she asked. She looked scared, almost frantic.

"Don't worry. We're here to help," Jackie said, trying to calm her while thinking fast at the same time.

"Who are you?" she repeated.

"My name is Jackie Chan. This is my brother John and our friends, the X-Men," was the reply. "What is your name?"

"My name is Cheetara," she replied.

"How is this door opened, Cheetara?" Cyclops asked.

"I don't now. I was unconscious when I was put in here."

"I could try to teleport in there if you vant me to," Nightcrawler offered.

"That okay, Cheetara?" Cyclops asked.

"Yes."

With that, Kurt was gone and right back where he started, well, except for the fact that he was thrown against the wall by something invisible.

"I think that there is something blocking my power."

"I think I see a lock. Stand back. I'm going to blast the door open." BAM! With his visor, Cyclops blasted the door open (fortunately, since none of them knew how to pick a lock). He then opened the door and helped her out.

Thank you. What is your name?" she said with relief.

"I'm called Cyclops, but you can call me by my real name, Scott, if you prefer."

They did a quick introduction of the X-Men, then set to work freeing Cheetarah's comrades. Their leader was Liono, and there was also Panthro, Tygra, Wily Kit, Wily Kat, and Snarf.

"We also have four other comrades trapped somewhere in the pyramid of Mumm-ra. It is important that we work quickly," Liono explained urgently.

Mumm-ra. So he's the one this tomb belongs to. Jackie thought. I better make a mental note of that. I just hope that Jade doesn't come in. Toru and Uncle are supposed to take care of her.

They found the cells where the four other ThunderCats were held. Wily Kit and Kat lost no time picking the locks. Pretty soon, all but one of the four were awake.

"We better not wake Lynxo up. He'll be grumpy," the one named Bengali said.

"Grumpy or not, we've got to get all of you out of here," Kitty said.

"What's going on? Where are we?" a tired voice asked. The noise had woken Lynxo up.

Using his telepathic powers, Professor Xavier said Don't worry Lynxo. You're safe. My name is Charles Xavier. My friends and I are here to help. The rest of your friends are with us. That just scared Lynxo even more.

"Lynxo, it's okay. Charles Xavier is our friend, as well as the X-Men. Their here to help us," Cheetara said to help calm him down. That helped a little, although Lynxo remained somewhat apprehensive. If Cheetara and the others trust this Charles Xavier, then they must be friends. Lynxo thought. Professor X. smiled to himself, as he had picked up on that thought.

As soon as they got out of the prison area and started back towards the door in which the X-Men and the Chan brothers had come in, the dog was seen, but not its master. They left, with the Thundercats, to the tents that they had.

"Jackie!"

"What, Uncle?"

"Jade is acting up."

"Toru was looking after her, wasn't he?"

"I was, but when Uncle came to ask me to help him with a chi spell, Jade ran off. We found her later going through Uncle's books."

"Where is Jade right now?" John asked.

"I'm in here!" Jade yelled from her tent, "and you can tell Toru that I don't like being tied up and my suitcase, sleeping bag, and pillow on top of me!" Jackie, John, Toru, Uncle, and the X-Men laughed, but the Thundercats didn't. They looked puzzled and looked at each other. When Cheetara made eye contact with Uncle, he looked at them and jumped a mile in the air.

"Jackie! Who are these people who are with you?"

"Uncle, relax. They are our friends."

"Can they be trusted?"

"Of course we can. My name is Liono, Lord of the Thundercats. These are my comrades, Cheetara, Panthro, Tygra, Wily Kit, Wily Kay, Lynxo, Bengali, Pumyra, Snarf, and Snarfer, " Liono said, naming the rest of the Thundercats in turn.

"Dad, I thought that you and Jackie were just going to examine the tomb."

"Jade, the situation has become more serious," John said.

"Can I help? Please?"

"John, she might be able to help if we need it," Jackie said.

"You would know," John muttered to his brother. "She's spent a year with you and your adventures."

That afternoon, the Thundercats explained their situation inside one of the bigger tents. They told Jackie, John, Uncle, Toru, Jade, and the X-Men everything that they knew about Mumm-ra. By the time that they had finished, it was evening. A quick supper was made. After supper, Uncle went off to check his books to do research on how to get rid of Mumm-ra and the Spirits of Evil. Although the rest of the group went into their tents, with the Thundercats sharing tents, Uncle, Professor Xavier, and Liono did not sleep. They were determined to find the right chi spell to get rid of Mumm-ra for good.

Meanwhile, Mumm-ra was watching the entire scene from the pool with Mar-Mutt looking in as well.

"So, that chi wizard thinks he can help the Thundercats truly beat me with his chi spells, along with help from Liono and whoever that is in the hovercar. We will see. Ancient Spirits of Evil, turn this being into Mumm-ra!"

With that done, he called the mutants, the Lunatacks, the Shadow Khan, Juggernaut, Magneto, Mystique, Toad, and Sabretooth. He explained the situation to them. They agreed to help-or rather, Mumm-ra forced some of them to help him with his plan.

The next morning, Mystique walked into camp disguised as someone who came to help with the archaeological dig. Using the name Cassandra Holmes, she asked to speak to Jackie and John. While she was speaking to them, Professor Xavier came out of his tent after taking a nap. He instantly recognized Mystique, even in her disguise.

Nice to see you here, Mystique. Are you here for something other then the archaeological dig or for the dig? He asked her telepathically.

Read my mind, like I know you can. As Magneto said, "Why ask questions to which you already know the answers?" Mystique thought back. Professor X chuckled to himself, but suddenly looked very serious. He went to see how Uncle was coming with his chi spells. When he got to Uncle's tent, however, he found Uncle in a fuss about something.

"How am I supposed to do the chi spell without the ingredients?"

"Uncle, I thought that you sent Toru out for them," Jade replied.

"I did. What good is an apprentice who can't get back in time with the ingredients?"

"Uncle, calm down before you scare Jade and our visitors. Toru will be back soon. I thought you had the ingredients with you," Jackie said.

"I do."

"Then why did you send Toru out for ingredients?"

"Because it is always good to have a backup chi spell!"

Just then, Toru came in with the ingredients. He looked like he had just seen a ghost.

"Toru, what's wrong?" John said, coming in after his talk with Mystique.

"If it was the Shadow Kan, I'll…"

"Jade, let Toru speak."

"Thank you, Jackie. Someone tried to attack me as I was coming back from the market. I didn't catch who they were, but 1 of them had a very long tongue, another had body armour, a third was wearing fur, and a fourth tried to grab my bag with some metal power before I knocked them out."

"Why would Toad, Sabertooth, and Magneto work with Juggernaut?" Professor Xavier mused. "Why also would Mystique show up?"

"Who are all of the people you've just mentioned, Professor?" asked Toru.

"Magneto, Toad, Sabertooth, and Mystique are a group called the Brotherhood of Mutants. Juggernaut is my half brother. All five have attacked my school in some way, shape, or form. Juggernaut has never shown an interest in becoming an ally with Magneto or any other member of the Brotherhood of Mutants. I fear that there is an ulterior motive to this."

Meanwhile the Thundercats where still sleeping in their tent. Lion-o woke as the sunlight shone on his face through an opening in the tent. In a split second he forgot where he was, and then remembered. He sat up with a start.

"Tygra you awake?" He asked.

"I am now" he replied. He sat up and stretched.

"That was better then being all crammed in those cells in the pyramid. Never the less, Lion-O, I suggest you think out our situation before deciding how to act."

"I am aware of that Tygra. Those people have been more then helpful. And with any luck we could be rid of Mumm-Ra once and for all. Third earth could be peaceful again."

"That's all and good" replied Panthro. "Although, we need to be cautious, we are in a world different to our own, we don't belong here. The people seem good although we just met... we have to get back as soon as possible"

"If we knew how to get back," snorted Wily Kat.

"Maybe that Mr Chan and that professor can tell us," suggested Pumyra.

"I hope Mumm-Ra didn't follow, he could easily done so" stated Cheetara.

"With any luck he didn't Cheetara. Right now, our best options to be friendly to them but please everyone be cautious. I am sure there is evil on this world as well as ours. And never leave alone, always at least stay in pairs"

By now, everyone had woken up listened in and nodded in agreement.

"Me, cheetara and Tygra and Panthro will go and speak to these people to determine our next course of action. Maybe they have this chi spell ready to destroy evil Mumm-Ra. Stay here and keep out of trouble"

And with that Lion-o, Cheetara, Tygra, Panthro left the tent and looked for the professor and the Chans.

As they approached them, Lion-O noticed they looked worried about something.

"Good day everyone, Is everything alright?"

The professor turned to Lion-O. "Ah Lion-O, good morning everyone, I trust you all rested well?"

"Yes thank you" replied Cheetara. "Did you manage to get everything you need for this chi-spell?"

"Yes we did my dear" replied Uncle "and a back up. But it seems some brotherhood of mutants have taken an interest to us"

"Brotherhood of mutants?" asked Tygra, concerned in the tone of Uncle's voice.

The professor explained who they where to the group.

"Humph. If that's anything to by, they are very much like the mutants we know back on third earth. In a word, trouble."

"Although as the professor explained, why would some of them work together when they wouldn't usually?" said Tygra concerned.

At that point Kitty busted in to the tent.

"Professor the brotherhood is approaching the tents with a whole load of new mutants, none like we have seen before!"

"Calm down kitty" said Professor X. "Describe them to me"

"Well there one which looks like a jackal, one is a big old frog and a white one that's like the scariest monkey ever!" Kitty took a breath. "They kept on saying destroy the Thundercats and the others"

"Jackalman!" said Cheetara.

"Monkain!" said Tygra.

"And Slithe" said Panthro in an angry tone of voice.

"Looks like the mutants have followed us back after all" stated Lion-O.

"But there is loads of others with them we don't know either!" exclaimed Kitty.

The Thundercats looked at each others worried faces.

All of a sudden a commotion of what is seems a fight starting outside.

"Keep the chi spells safe Uncle" said Jackie." Jade, STAY WITH UNCLE. This is serious!" Jade reluctantly nodded. The group went outside leaving uncle and Jade in the tent to see what the commotion was.

"Jade, do not think about following Jackie!" Uncle said. "I will need your help now that Toru is helping Jackie and the others! One more thing! Get dressed. An assistant should not be wearing pajamas while working."

"You should talk. You're wearing boxers!"