Doctor Daniel Jackson didn't know it yet. But as he reflected on some of his experiences, an evil being would take his mind back to an evil time.

So that's what happened.

Aboard the timemobile, a sleepy Daniel reviewed the events. .

The team stopped a Vulcan from colliding with Joe Chill so that once again Bruce Wayne's parents died.

When Clark learned this, he was pretty upset. Even tried to use their time-travel-Stargate to go back and undo it.

Things didn't get much better when Team MacGyver paid a visit to Home Base.

"And so that's how the rogue Q gave all this power to the Joker," Daniel said. "That's also how the Q formed an alliance with the Ancients. Now go to sleep, you guys!"

Howard Wolowitz and Raj Koothrappali both snickered.

"I'm sorry," Howard said in his slightly nasal voice. "Could you repeat that, please?"

"Yes, could you repeat that?" Raj asked in a more high-pitched voice that sounded like he was laughing and talking at the same time.

While Angus MacGyver and the Punisher grumbled in the background, Daniel let out a noise of frustration, a noise much like a groaning roar, then he dutifully recited from the Background.

He talked as quickly as he could.

It was a terrible night at Home Base. Everyone was in the Gate Room, on the floor in sleeping bags. Because the Joker had set up force fields to keep them out of their rooms.

The next morning, Daniel stumbled past the "Enterprise" rooms and the rooms that looked like rooms on the Kent farm. Including the one that looked like the loft in Clark's barn, complete with artificial sunset.

At the breakfast table, everyone looked very tired. Sam was simply playing with her food.

"Easy for you, Clark," a bleary-eyed Colonel Jack O'Neill said in a tired mumbling voice. "You've got your room at home to sleep in. I've got my quarters at the base to sleep in. When the Joker isn't keeping me out, that is."

"Yeah," Clark Kent said as he forked up some scrambled eggs and bacon. "But my parents aren't here. Or my friends."

"That may be," Leonard Hofstadter said as he forked his own food. "But maybe we can find a way to help you, Clark."

After breakfast, Daniel took a seat in the Kent living room. There, he was approached by Leonard and his roommate Sheldon Cooper.

"Doctor Jackson?" Sheldon said quietly. "I'd like to apologize for the behavior of my associates."

Daniel thought how ironic it was that Sheldon was considered the insensitive one. Yet here he was doing the apologizing.

"Yeah, we're sorry, Doctor Jackson," Leonard said with an apologetic look. "Even if they were under the influence of the Joker."

"Thanks, guys," Daniel said.

It was then that Howard and Raj approached, both with their heads bowed.

"We probably wouldn't have been under the influence of the Joker if we weren't so obnoxious in the first place," Howard muttered.

"We really are very sorry, Doctor Jackson," Raj said with his own sad apologetic look which one might see on a puppy.

A slight grin from Daniel. "It's okay, guys. And call me 'Daniel.'"

"Oh!" Raj exclaimed as he lit up. "Doctor Jackson says I can call him 'Daniel!' That is so cool!"

"By the way. Doctor Jackson?" Sheldon said. "That's where I sit."

Daniel thought how later the guys got one of their not-so-great ideas. But as usual, their hearts were in the right place.

"What are you guys doing in here?" O'Neill demanded as he stepped inside the holodeck.

Much like with the Stargate, O'Neill was transported to another place.

In this case, it was an apartment in Pasadena. One filled with white boards and a model of DNA. And while there were plenty of superhero action figures, there were no snakes (O'Neill's term for Goa'uld symbiotes). But there were the four scientists from Team MacGyver and Clark.

With his usual slightly worried look, Leonard turned to face O'Neill.

"We're just showing Clark episodes of 'Smallville,'" he said meekly with a slight shrug. Even indoors, he wore a hooded jacket with the hood down.

"Guys, that is not a good idea," Daniel said.

"Knowledge of the future could be very dangerous," Major Samantha Carter said.

"Or it could be very helpful," Sheldon said in his slightly prissy voice.

"How'd you even get these episodes?" Sam Beckett asked. The quantum-leaper for the SG-1 time travel team looked like he had his eyes closed. Probably from lack of sleep.

With a slightly imperious look, Sheldon crossed his lanky arms over his Flash T-shirt. "When you know the laws of physics, Doctor Beckett, you can do anything. You of all people should know that."

A hologram figure spoke.

"Take it easy, all you S-G-One people. The guys are only trying to help." The actress-waitress Penny was neighbor to Leonard and Sheldon back in their real apartment building.

Carter looked slightly annoyed. "I'm not going to argue with a hologram."

With shoulders slightly hunched, Leonard held out his hands in a kind of defensive gesture. "We were just thinking what if Clark gets thrown somewhere unfamiliar on a timeline?"

"Yeah, the timeline thingy," Penny said.

Now O'Neill looked annoyed. "Do you even know what's going on here, blond person?"

"As a rule, no," Penny admitted in a blithe tone.

Leonard went on. "We were just thinking about things that could happen. What if the Joker threw Clark somewhere where he met a young Lois Lane? Or Tess Mercer?"

"Oo-la-la," Howard said with a smile. Next to him, Raj also smiled. Until Colonel O'Neill's frown made them both stop.

More of the hands out from Leonard. "If he doesn't know anything about Lois or Tess, he could really mess up his own future. And a lot of other people's future, too."

With a slight frown, Clark sat at the center of the group right next to Sheldon's spot. "So far, guys, I've learned a lot."

"See?" Sheldon said. "By the way, hello to you, too, Colonel O-Neill. Major Carter, Doctor Jackson, Teal'c."

"Greetings, Sheldon Cooper," Teal'c said with a grin and a slight bow.

"Hey, guys," Daniel said. Carter put her hand up in a frozen wave. O'Neill simply pointed a finger.

"Letting Clark know about his future," Leonard said. "That's all we were thinking."

"Well, I was," Sheldon said. "I do most of the thinking in the group."

"Thank you, Sheldon," Leonard said in his usual miffed voice he used with his roommate.

"What if he were to meet Lois Lane or Tess Mercer. Or both," Raj said with a dreamy look. "I'd like to meet them both."

"Thank you, Raj," O'Neill said. "Your input, as always, is very valuable."

"Hey! I'm an astrophysicist."

"So am I," Carter said.

Penny looked stern, if that was possible for the perky blonde. "Are you picking on my friend Raj?"

"No. But what if I was?" Carter said in a challenging tone..

Penny narrowed her eyes. "Okay, Major Carter, you and I are about to have a serious problem. I just might have to go all Nebraska on you."

Carter removed her jacket. "Bring it!" She was still a little testy from the last time the Joker had temporary control of her.

"Oh, it's junior rodeo on!" Penny said, clenching her fists.

"Cat fight!"

Teal'c stood between Penny and Major Carter.

"Easy there. Settle down, everyone," O'Neill ordered.

"Still," Clark said. "What the guys are doing makes a lot of sense."

"For once," O'Neill said. "I guess anything is possible."

"It is," Howard mumbled. With Teal'c standing very near, he slowly looked up and stared. Then he spoke in a pleading tone. "Please don't eat me, Teal'c!"

Teal'c looked more grim than usual. "As I have told you many times before, Howard Wolowitz, I am not a cannibal."

"But you are very large, buddy. Humongous, in fact." Howard leaned in toward Raj. "Is it just me or has Teal'c gotten even bigger?"

Teal'c's eyes narrowed slightly. "You have commented on my size many times as well."

"Well, a small moon could orbit around you."

"Not possible, dude."

Daniel wore his usual intense look as he leaned in toward O'Neill. "Jack, I'm not so sure this is a good idea, with everything Clark's been through."

"I'm thinking, Daniel." Wearing his own intense look, O'Neill considered. Then: "Hard as it is to believe, you guys may have a point."

Sheldon's head went back and forth as he looked mildly surprised. "Why, I always have a point, Colonel O-Neill. And it's always a good one. But especially this time."

"Right you are, Sheldon," O'Neill said. "Clark needs to know something about his future." With a slight nod, O'Neill headed for the exit. "Carry on, guys."

"Hold up, guys." Outside the holodeck, Daniel whispered to his team mates. "I still think we should be there to help Clark, guide him through this."

"You are correct, Daniel Jackson."

"Sounds good," O'Neill said as he headed back into the holodeck. "Room for a few more, guys?"

"Certainly! Welcome back, Colonel O-Neill."

"Thanks, Sheldon."

"Thai food?"

Something happened in Daniel's mind just then. It was like static appearing on a TV screen.

In his mind, Daniel jumped back in time.

When Team MacGyver first arrived, it was the usual roster: Raj, Howard, Leonard, and Sheldon. The four scientists known as the "Big Bang" guys. The ones who built the space-time tunnels for the time travel teams.

With the guys were the team's two Men In Black, L and M, along with Frank Castle, better known as the Punisher. And their adventurer-inventor captain.

But Michael Westen and Hawkman were also with them.

As Daniel recalled, Michael spent a lot of time complaining and lecturing.

"If you're trying to interrogate a spy," he said in a cool measured tone, "you might want to use aliens that are a little more convincing. I suggest not using Romulans and Klingons. They're from 'Star Trek.' And therefore completely fictional!"

Wearing his usual light gray suit with no tie, Michael gestured to the figure next to him. "And what's with the birdman? Is he advertising a pet shop somewhere in Miami?"

"Stuff it, spy boy," Hawkman grunted as he waved his mace. "Or I'll stuff you and put you in my museum."

"I'll take you home now," Angus "Mac" MacGyver said.

Abruptly, Daniel's mind jumped to a time that was more terrifying.

When a dark being manipulated his mind.

It was inside a concentration camp on a world called Dark Vulcan.

On the floor of the concentration camp tunnel, Daniel was able to gasp for air. But that was it.

Did he hear chains rattling?

Come on, Daniel, stay awake, he told himself.

As he struggled to stay conscious, he tried to recall pleasant memories from his past.

In the holodeck apartment, Clark sat with his head bowed. Daniel realized he had a lot to deal with.

"I can't believe Lex and I become enemies," he said.

The others had tried to offer support and encouragement. But now they were gone. Off on an emergency mission that combined parts of SG-1 and parts of Team MacGyver. They would, of course, require additional Rest when they returned..

After a certain number of time travel missions, team members had to go into a period of relative inactivity known as Rest. It was the only way to continue time travel or "time-jumping," as Jack called it.

"Hey, Clark?" Leonard said quietly. "We heard about the whole thing with the Vulcan guy and Joe Chill and Bruce Wayne's parents."

Daniel saw a brief flash of anger in Clark's face. Much like when Clark argued with Jack.

Then it was gone.

"Yeah, that was not so great," Clark said. "I wish this whole thing was over."

"Me, too," Sheldon said as he ate Thai food in his usual spot. He grinned. "I'd like to meet Bruce Wayne's parents, though."

Leonard made a face. "At the moment they got shot?"

"No, not then," Sheldon said. "I mean if they actually lived."

"That did not turn out so great, Sheldon." Daniel quickly explained how the team had to go into the 31st century to fight Imperial Guards. In a universe where Bruce Wayne never became Batman, Earth was ruled over by dictators for hundreds of years.

"Isn't there a little dictator inside each of us?" Leonard mused aloud.

"Isn't that what you always say, Doctor Jackson?" Sheldon asked.

"I've heard Daniel say that or something like that," Clark said. "He may be right. Daniel's usually right about a lot of stuff."

"Maybe the dictator thing. But I don't always know everything.."

"Even though you carry the Background?"

"Even with that, Raj." Daniel placed a hand on Clark's shoulder. "Hey, Clark. Look. I realize it's not easy right now. Finding out about Lex."

"Yeah, I can't believe we become enemies," Clark said. "I remember I stood there on the loft with him. It was right after all that stuff with Kyle Tippett and Bob Rickman. I said how they used to be best friends. I asked Lex, 'Think we'll ever end up like that?' Lex said, 'Trust me, Clark. Our friendship is going to be the stuff of legend.'" He shook his head. "And now it's all over."

"But it's not, Clark. You'll go back. You'll have that friendship with Lex again. For a while longer." Gently, Daniel massaged his shoulder. Much as Jonathan Kent sometimes did with his son.

Clark shrugged. "What's the point?"

Silence. They all just sat there looking glum. Except for Sheldon chewing his food with a blank look.

Inwardly, Daniel sighed. Maybe this was really not such a good idea after all.

Was there anything he could say?

"Clark," Daniel said. "It doesn't matter who you are. No matter how many powers you have, you can't change everything or control everything."

"I'd certainly like to, though," Sheldon said. "Could I get powers like the Joker has?"

"Just what we need," Howard groaned.

"Yeah, a bunch of universes filled with trains," Raj said.

"Trains and monkeys," Sheldon corrected, holding up a finger. "And each city would be a Sheldonopolis!"

"Oh, boy," Leonard said.

"Guys, even if we were all-powerful, we can still get hurt and we can still feel pain. Just like some of the powerful beings in Captain Kirk's time. Like Charlie X."

"That's a good episode," Sheldon said. "If I had those powers, I'd know how to use them."

"Be careful, Sheldon," Daniel said. "No matter how smart you are, you can misuse what you have. I know I did once."

"I wouldn't make your mistakes," Sheldon said.

Daniel responded with a wry grin. "Of course you wouldn't, Sheldon."

"What about that time you tattled on me to the F-B-I?" Howard grumbled.

"That turned out all right for me!"

Now Clark wore his own grin. "Does anything get you down, Sheldon?"

"Quite a few things, actually," Leonard said with his usual wincing look.

Daniel sometimes wondered: What were the Q and the Ancients thinking, doing this to mere mortals?

And what about Clark? He might have powers and abilities far beyond those of mere mortal men. But he'd definitely be better off back in Smallville.

"Well, Clark," Leonard said. "We just want you to know that powers or no powers, you're a true hero to us."

"Yes, Clark," a beaming Sheldon said. "You are a true hero. Just like the Flash. Maybe better."

Clark smiled. "Better than the Flash, huh? Thanks, Sheldon. From you that means a lot."

"You're quite welcome, Clark," Sheldon said with a grin as his head bobbed slightly.

"It's true, dude," Raj said, now bereft of his Romulan ale. "You're a true super-dude. Or as Lois Lane might say, 'you're a true red-and-blue super-dude.'"

"You do wear red and blue a lot," Howard said.

"But what matters most is you're a great guy," Leonard said.

"Thanks, guys," Clark said quietly. "I don't always feel like much of a hero, though."

"Well, it's not just us," Raj said. "Lois Lane thinks you're a hero, too. Along with Chloe and Lana."

A slight nod and grin from Clark. "That's great, Raj. But sometimes I wonder: can I do all this? Save people. Help people. It's a lot of pressure. A lot of responsibility. There's so much to live up to. Especially now with changing time and everything."

"Well," Leonard said with a smile. "Just keep doing what you can, Clark. It'll all work out."

"No, it won't," Sheldon said.

"Yes, it will, Sheldon," Daniel with gentle firmness.

"With all due respect, Doctor Jackson, there is no definitive proof of that."

"Things always work out, dude," Raj insisted.

Howard turned to Daniel. "So, Doctor Jackson. What was it like being an ascended being?"

"Yeah, what was that like?" Raj asked with an eager smile.

Daniel winced slightly. "Well, guys, I don't remember that much. Just sort of a sense of things really."

"Well, Stuart from the comic book store would love meeting you! And Clark!" Leonard wore a great big smile. "You should come with us some time."

"You should, dude!"

Daniel was pulled out of that pleasant memory and thrust into his mental struggle on Dark Vulcan.

He recalled the creature being very near..

Daniel could sense the physical presence of the dark being, hear his breathing.

He's standing right over me!

Daniel tried to reach out to grab him but he was frozen, unable to move..

The being was using Dark Power to probe his mind, it seemed.

Maybe even manipulate his memories.

Daniel went back into the past again.

To Home Base and the guys right after Clark saw episodes of "Smallville."

"I don't really want to go back home to my mother," Howard said. "It's different for you, Clark. You've got Jonathan and Martha Kent. The perfect parents."

"Sorry about your dad, by the way," Clark said.

"Thanks." Howard smiled.

"Howard is lucky in a way," Raj said. "At least he hasn't turned into a meteor freak."

"What are you talking about, Raj?" Leonard asked.

"Yes, Raj," Daniel said. "What are you talking about?"

"In Smallville, anyone with a really bad parent goes psycho," Raj said. "And if they get powers from meteor rocks, it gets even worse. Because then, you know, it's a psycho with powers."

"That's true in way," Clark said. "Wish there was a way to help them."

Another hand on the shoulder from Daniel. "That's why you're a hero, Clark. Because you always want to help people and you look for the best in them."

Leonard smiled. "What he said."

"I wouldn't mind having powers," Howard admitted. "Though I hate to think of my mother exposed to meteor rocks." He shuddered.

Next to him, Raj beamed. "But you know what? Being on a time travel adventure is so cool!"

Howard bowed his head slightly, less in a respectful Teal'c way, more in a Howard hangdog way. "Except for that time we kept you up all night, Doctor Jackson. Sorry again."

"Yeah, sorry, dude," Raj said. "Again."

"It's forgotten," Daniel said. "You know, guys, we're on a serious mission. But it's okay to have fun. As long as it's fun in the right way."

"Like the kind of fun that doesn't bother someone else," Leonard said pointedly.

"Exactly, Leonard. It's been great watching 'Smallville' with you guys," Daniel said.

"Maybe we could watch 'Star Trek' together, too!" Raj enthused.

"Maybe," Daniel said.

"Or 'Stargate!' Your show!" Howard exclaimed.

Just then, Daniel got a sense from the Guardian that something very big was going to happen.

"Doctor Jackson?" Howard said. It snapped Daniel out of his thoughts.

"Yes, Mister Wolowitz?" Daniel emphasized the word "Mister."

Briefly, Howard made a face. "Even though we messed up, can we still call you 'Daniel?'"

"Or you could just call me 'dude' like Raj does," Daniel said in his slow quiet way of talking.

"Yeah, dude!" Raj did a "raise the roof" gesture..

"All right," Clark said. "Good for you guys."

"Look, guys," Daniel said. "Even if we don't go on missions together, we're still friends."

"We're friends?" a giddy Raj said. "We're friends with Doctor Daniel Jackson!"

"Wait until Stuart hears about this," Howard said. "We're friends with Daniel Jackson. And Clark Kent!" ..

In his mind, Daniel left behind the happy scene and traveled back to when he was on Dark Vulcan.

Was it the Joker manipulating his mind?

Or was it...him?

Lying there on the floor in a semi-conscious state, Daniel thought how even though things went wrong with Clark later the encouragement offered by the "Big Bang" guys probably helped.

More than some of the things SG-1 did.

They must have been under some influence by the Joker because they didn't handle that situation with Clark in the most sensitive manner.

No, the aftermath of the Bruce Wayne incident wasn't handled well at all.

But, Daniel remembered, there was still some hope.

It was while Leonard, Raj and Howard were watching "The Trouble with Tribbles." Daniel stood outside a holodeck entrance with Clark and Sheldon.

The door whisked open, and Daniel glimpsed the entrance to the Talon.

"Go ahead, Clark," Sheldon said quietly. "Going home for a while helped me."

"I see that," Clark said.

This is what Clark does, Daniel realized. He befriends outsiders. Whether it's Cyrus Krupp or Jordan Cross. Or the "Big Bang" guys. Clark even tried to reach out to Davis Bloome. Of course, Raj and Howard weren't about to turn into monsters. Or at least Daniel hoped they wouldn't. But who knew what the Joker might do?

As Clark stepped inside, he found a friend near the entrance. .

"Clark," Lex said cordially as he lifted his coffee cup.

"Hey, Clark," Pete Ross said with a big smile.

"Hi, Clark!" Both Chloe and Lana waved. Both had big smiles.

Then the voice of Martha Kent. "Clark! You're back!"

"Hey, Mom."

"Good to have you back, son," Jonathan said, putting a hand on his shoulder. .

"Good to be back. This is my buddy Sheldon."

"Hello, Sheldon," Martha said, smiling as she shook his hand. .

"How are you, Sheldon?" Jonathan wore a big smile as he vigorously shook hands with the lanky physicist..

"Hello, Mister and Missus Kent."

Clark was home.

As the door shut, Daniel turned his mind to more pressing matters.

The new crisis that was brewing.

Daniel snapped out of it.

He was back aboard the timemobile. To collect himself, he reviewed the basic situation.

Despite what the guys and SG-1 speculated, Clark didn't end up in the past with Tess Mercer or Lois Lane.

Instead, he ended up in the past with Edith Keeler. A mission director in Depression-era America. A woman who was the subject of a time travel mission by Captain Kirk, Spock and Doctor McCoy.

It made sense the Joker would send a dazed and disoriented Clark there. The death of Edith Keeler was the central event in the Prime Universe. That moment in time even had a code name: Target Zero.

What happened was this: Doctor McCoy went back in time through the Guardian of Forever. While there, he apparently stopped Edith Keeler from dying in a traffic accident. At least that's what Spock logically deduced later.

As Kirk and Spock discovered, McCoy's action resulted in Edith using her peace movement to keep America out of World War II. Hitler and the Nazis then developed the H-bomb first. With that power, Germany ruled the world.

Daniel wondered what it was like for Edith and Doctor McCoy to live in that timeline. Thankfully, Kirk and Spock succeeded in correcting it.

Except now the Joker had created another bizarre new timeline where Captain Kirk and Spock lived in Smallville and Lex Luthor became Emperor of Earth.

Daniel was brought out of his thoughts by a familiar voice.

"Hey, Doctor Jackson," Raj said. "Or should I say 'Daniel?'" he asked with a sly grin.

From his seat on the timemobile, Daniel looked up. "Hey, guys. What have you been doing while we're on this little trip?"

"We were just talking to Jonathan and Martha Kent," Leonard explained with a smile and just a hint of pride.

"Actually, cosmic beings taking the form of Jonathan and Martha Kent," Sheldon said.

Daniel nodded in understanding. Since the Q and the Ancients were working to hold back some of the Joker's power, they had created intermediaries: cosmic beings who assumed the forms of prominent people in the Prime Universe.

"I've met them," Daniel said. "From time to time, we've run into the cosmic beings. Including your friend 'Cosmic' Chloe Sullivan."

"She gave us the ability to mind-meld with Kirk and Spock," Leonard said with a grin.

"When we got sucked out of the timemobile," Howard noted drily.

Daniel knew the basic situation. The Joker had arranged to turn Clark into a hybrid of the Hulk, the Green Goblin, Doomsday and a Klingon. It was not fun for the guys.

Once the Clark-Creature, or "Clark-Hulk," as Howard called him, punched a hole in the timemobile, the guys ended up in Smallville in the past. There, they got to meet two of their "Star Trek" heroes.

Maybe Howard had even treated Captain Kirk to an embarrassing impersonation. Howard did sometimes impersonate Stephen Hawking. Daniel didn't really care for that impersonation. But he did enjoy Howard's celebrity impersonations of Al Pacino and Nicolas Cage.

Nearby, Beckett spoke in a tired voice. "Time travel is rarely simple. Sometimes you shouldn't intervene. But sometimes it's okay if you intervene in the right way."

A tired grin from Daniel. "You would know, Sam."

Lifting his chin, Leonard smiled. "Thanks to the Doctor Fate helmet, Chloe could see the future. So she knew what was okay to do. It's not like the Joker changing the past just to mess things up."

"The Joker is crazy," Sheldon said, shaking his head.

"And Sheldon knows crazy," Howard mumbled.

Daniel thought how it wasn't over yet. And he already knew that once the team got to Target Zero the Joker had a Terminator waiting for them.

Also waiting was Dark Spock.