Author's Notes: This is the first time I've written the tenth Doctor and Donna. I'm not sure how well I've done with them but hope you enjoy anyway.

The light was blinding.

He felt like his eyes were boiling in their sockets, his skin was bubbling and every part of him was burning. His lungs felt like they were frozen but, trying to breathe, fire seared through him.

Death was apparently not as peaceful as he'd hoped it would be. So far there was nothing other than light and pain. The people he wanted to see weren't there and he was beginning to doubt he would see them.

The burning stopped suddenly, and his body met solid ground. Taking a long slow breath he pushed himself off the ground to try to look around, but as he lifted his head the world began to spin. Pain shot through his temple and Rip Hunter fell into unconsciousness.

x

"Doctor," Donna called, stalling when she stumbled across a body as she walked to her room in the TARDIS.

Shaking his head the Time Lord headed after his friend, "What's wro…" he trailed off seeing the man lying unconscious in the middle of the corridor, "Where did he come from?"

Donna shrugged, "No idea. He was just lying there when I came round the corner."

The Doctor crouched to look at their visitor, grimacing in thought, "And how did you get onto my TARDIS?"

"Seems you've got a fan," Donna chuckled, rolling her eyes when he looked up at her confused, "Look at his coat."

The Doctor frowned at her, "Help me get him to the infirmary."

Donna slid her arm under one of their guests hoisting him up with the Doctor, "He's even skinnier than you."

Ignoring her the Doctor led them three doors along and into the infirmary, which Donna would swear had not always been there. They rested the man on the bed and the Doctor started tapping controls on the wall beside it.

"Hmm," the Time Lord mused as he studied the readouts, "That's…odd."

"What's odd?" Donna demanded worriedly.

The Doctor frowned even more, "According to this he is human but he's soaked in Artron energy." At Donna's expectant expression he continued, "It's what the TARDIS uses to travel through time."

"Really?"

"Not exactly," he admitted, "Think of it like this. Every time we travel through the time stream you get a small, tiny, minute dose of Artron. A bit like background radiation when you use a microwave but his cells are saturated with it."

Deciding not to pursue that specific conversation Donna asked, "Is it dangerous?"

"He should be dead," the Doctor confirmed, "With the amount of energy flowing through him he should have died almost instantly but…"

"But?" she encouraged.

The Doctor frowned in thought, "Somehow instead of it incinerating him he's absorbed it."

A low moan from the man made them turn to find he was forcing his eyes open.

"Time for some answers," the Doctor said intently.

Donna shook her head and moved him back, "Let me. Considering…well you."

The Doctor smiled slightly. One of the things that had drawn him to Donna was her kindness to others. She may be loud and pushy at times, but she cared so deeply. The man on the bed finally managed to open his eyes and focus on them whispering, "Gideon."

"You're safe," Donna told him, "What's your name?"

Swallowing hard the man breathed, "Rip...Rip Hunter."

"I'm Donna," she introduced herself, "And this is the Doctor."

Rip glanced over at the Doctor before asking Donna, "How did I get here?"

"We were hoping you could tell us," Donna replied.

He grimaced, "I was in a field then…I…it's kind of fuzzy. I remember light."

"You're soaked in Artron energy," the Doctor spoke up, "And now in my TARDIS."

Rip grimaced, a headache obviously plaguing him by the way his eyes were squinted against the light, "Artron energy? TARDIS?"

"Doctor," Donna turned worriedly, "Do we have painkillers we can give him?"

The Doctor frowned again, "Rip, I need you to look at me."

Looking up at the Doctor, Rip pulled away when the Time Lord scanned him with the sonic crying out in pain before his eyes rolled up in his head and he collapsed on the bed once more.

x

Rip floated in the blackness, straining to hear the voice calling to him. His head felt like it was going to explode, the burning starting once again.

"It's okay," a man said when Rip was flung back to consciousness gasping for air, "Breathe."

Rip fought to calm his breathing, trying to follow the Doctor's example as well as remember his lessons on how to centre himself.

"That's it," the man soothed when Rip's finally managed to calm himself and breathe properly once more, "Good. That's better," he rested a hand on Rip's shoulder, "Hello, again."

"I'm not dead?" Rip whispered sadly.

The two people standing by the bed he was laying on looked at one another worriedly, before Donna asked softly, "Why is that a bad thing?"

The Doctor rested his hand on Donna's shoulder, "Let me talk to Rip alone."

She glanced at Rip for a moment before she left the room and the Doctor pulled over a chair.

"Living is not a bad thing," the Doctor said softly.

Dropping his eyes Rip shrugged, "I just expected not to survive."

"Survive what?" the Doctor asked kindly.

Rip sighed. This man had saved his life and, from what Rip could tell, was in control of the wherever he was. There was no way Rip could avoid this conversation.

"I overloaded the core for my ship's time-drive to stop a Time Demon," Rip explained, "The odds that I survived were…" he shrugged again, "Astronomical."

"That's what happened," the Doctor replied before pressing, "Why did you want to die?"

Rip dropped his eyes, "I didn't…I just expected…" he looked back up at the Doctor who was watching him intently and shrugged hoping to sound nonchalant, "There are people I hoped to see again."

He winced, pain shooting through his head again and a strange buzzing sounded in his ears.

"Rip?" the Doctor asked worriedly.

He rubbed his temple, "Just a small headache."

The Doctor frowned, "I don't think that's a small anything."

Before he could reply the pain increased and Rip pressed the heel of his hand against his temple.

"Okay," the Doctor said, "I'm going to give you something for the pain. This will knock you out again but it'll hopefully give me some time to fix whatever is causing this."

Rip nodded sighing in relief when he was sent back into comfortable blackness.

x

The Doctor studied the information on the screen before him regarding the man unconscious on the bed. As well as the energy soaking Rip, there was also a telepathic signal being directed at the man but it seemed to be distorted which was the cause of the pain.

Grimacing the Doctor realised it was the TARDIS itself distorting the signal.

"Doctor?" Donna called, "Can I come in?"

Turning he motioned her to join him while he continued to study the readouts.

"What did you do?" she demanded seeing Rip unconscious once more.

The Doctor shook his head, "I had to knock him out again. There is something trying to connect to him telepathically. The TARDIS is trying to protect him."

"I'm guessing that's a problem," Donna frowned.

The Doctor grimaced, "I don't want to let it through unless I know it's not going to harm him or us. I just need to find a way to block it completely."

"Do you know where he came from yet?" Donna asked, picking up a blanket to rest it over the man on the bed, "And how he got onboard?"

The Doctor nodded, "The TARDIS found him floating in the timestream, she brought him onboard. Where he comes from is another matter entirely."

Donna rolled her eyes, "Which means?"

"The energy in his cells are the wrong frequency for this universe," he explained.

She frowned, "That means…what?"

"Rip is from another universe," the Doctor replied, "When the core to his time drive exploded it threw him into this one. Which explains a lot."

Donna stared at him amazed before asking, "Another universe? Can we take him back?"

The Doctor shook his head, "Not possible. Not now the Time Lords are gone."

"What do we do?" Donna asked.

"At the moment we let him sleep."

Rip sat in the small kitchen which looked completely out of place considering the rest of what he now knew was a ship. He'd woken and this time the pain was gone which meant the Doctor allowed him out of the infirmary.

"Here you go," the Doctor put a mug of tea on the table in front of him.

Picking up the mug enjoying the feel of the heat in his hands Rip nodded, "Thank you, Doctor. For everything."

"It's not often I meet a fellow time traveller," the Doctor noted, "Not for some time anyway."

Drinking the tea Rip noted the sadness and loss reflected in the other man's eyes. Something he knew and understood well.

"So, I'm in a different universe," Rip sighed in thought, "I'm guessing that will make getting home a lot more difficult than I hoped."

"I'm afraid so," the Doctor confirmed, "Crossing universes is something that isn't easy to do."

Rip let out a long sigh before shrugging, "It's not like I had anything or anyone back there anyway."

"Well that is just incredibly hurtful," a familiar voice made him spin.

Rip stared at the woman standing there, "Gideon?"

"It is wonderful to see you, Rip," she smiled warmly, "I feared you were dead. I am so relieved you're safe."

The Doctor looked at him confused, "Who are you talking to?"

"You can't see her?" Rip asked standing to move closer to the human form of his best friend.

"Not yet," the Doctor mused, he opened a panel beside the fridge and hit a few buttons, "And now I can. It appears the TARDIS decided your friend is not a threat."

"The TARDIS understands that I am here to find my Captain," Gideon stated primly, throwing a dark look at the Doctor.

Rip smiled slightly before admonishing, "Gideon, don't be impolite. The Doctor helped me."

"He has been preventing me from contacting you," she replied sharply.

The Doctor gave her a look of contrition, "My apologies, Gideon. Due to the circumstances I needed to ensure the signal being received was safe, for all of us."

Gideon frowned slightly before she shrugged, "As you cared for my Captain I will let it pass this time."

Rip forced the amused smile off his face, relieved when Donna walked in. The red-head stalled and stared at Gideon.

"Should I ask?" Donna demanded.

"Maybe later," the Doctor replied.

She took another look at Gideon before telling them, "There's something strange in the control room."

x

Rip watched the Doctor and Donna leave the kitchen, torn between wanting to know what had appeared and talking to Gideon.

Gideon won.

"How are you here?" Rip asked, moving closer.

"I'm not, Captain," she replied softly, "You know that."

Rip sighed, "Not exactly what I meant, Gideon. How are you…" he trailed off gesturing around the room, "Here?"

"Oh," she smiled at him, "During the Cognitive Intrusion we telepathically linked and I…"

"What?" Rip demanded when she trailed off looking guilty.

She stepped slightly closer to him, her eyes soft, "I did not fully disconnect from you. I had to be able to keep tabs on you somehow when you left me."

"Gideon," he whispered sadly, "I didn't leave you. It wasn't meant to be for more than a few weeks. I needed to get my head straight after everything that happened with Thawne. Then you were trapped with the team and I needed to create a whole damn organisation to repair the damage they made."

"Captain…"

"And look how well that went," he snapped.

"Captain…"

Rip sighed, "When I finally got you back you left me a few months later."

Gideon frowned at him, folding her arms across her chest, "You asked me to go with the team."

"You didn't have to agree," Rip shrugged, knowing how childish he sounded.

She gave him a disapproving frown, "My recollection of the conversation was you asking me to do this because it was extremely important. That no matter what happened I had to stay with them to stop Mallus."

"I know."

"You never told me that you would leave, Rip," she whispered, "That I could lose you forever."

Rip shook his head, "Gideon…"

"Which is why I am here," she told him softly, "To find you a way home to me."

Rip smiled at her, "What about the team?"

"What about them?" Gideon replied, "The Waverider and I belong to you, Captain. You know that."

He frowned, "And you know what I mean, Gideon."

"I am perfectly capable of being here with you and running the Waverider," Gideon remined him before shrugging, "Besides, they are currently all on vacation after defeating Mallus."

"Lucky them," he shook his head softly, "I don't know if it'll be possible, Gideon. I could be stuck here."

"You forget who you're talking to," Gideon reminded him, "I will find a way to get you back home to me."

x

"Rip," Donna called, appearing in the doorway, "The Doctor wants you in the control room. There's something you need to see."

Gideon frowned annoyed at the interruption but didn't say a word when Rip held up his finger to stop her making a comment.

"We can continue this later," Rip told her, "You've proved I can't get rid of you. And I would never want you anywhere else."

She nodded, "Of course, Captain."

Rip followed Donna out the room along the corridor,

"Who is she?" Donna asked with a grin.

Rip shrugged, "That's Gideon."

"And she is?" Donna smirked amused.

"My dearest friend," Rip replied with a quick shrug.

Donna nodded, "Yes, that exchange was between 'friends'."

"What does that mean?" Rip demanded.

She gave him another amused smile before heading up the stairs into the control room. Rip paused staring at the room before him.

"I could spend weeks taking the engines of this ship apart," Rip mused studying the main console his eyes alight with curiosity.

"Another time," the Doctor told him, "Come and look at this."

Rip moved to join the other man who was looking down on a small glowing shard, "It's part of the core."

"Doctor," Donna cried.

"Rip, step back," the Doctor ordered sharply.

Confused Rip turned to him, "What's…" he stared as he saw his hand beginning to glow, "I'm going to move back."

Taking several steps away Rip let out a sigh of relief as the glow faded once more.

"It's your proximity to the core," Gideon spoke up making them all spin, "Captain, I believe this may be your way back home. However, it is best that you perform tests and not do anything stupid or reckless, as you normally do."

Donna chuckled, "I like her."

"And she's right," the Doctor added.

Rip nodded, "She usually is."

"Who are you exactly?" Donna asked the woman who was sitting on the rail watching the two men nearby.

"I am Gideon," she gave a slight nod, "I am the Artificial Consciousness of the Waverider, Captain Hunter's ship. My main function is to protect him," she sighed sadly, "One I have failed in recently."

Donna took this in, "Is this how you always look?"

"This is the form I have always taken within Captain Hunter's mind," Gideon explained, "It makes it easier for us to converse at times like this."

Donna gave a nod smiling to herself as she turned to where Rip and the Doctor were testing how close Rip could get to the core.

"Are you actually going to do any tests or are you two just going to keep playing?" Donna demanded.

The two men turned to her.

"We've worked out how close Rip can get to the core," the Doctor explained, "And I've placed a forcefield around the shard for the moment. Just to make sure that he doesn't accidentally touch it."

"Good," Gideon noted, "We want no more accidents."

Rip sighed, "Please let it go."

"Once you are home where you belong I will," Gideon replied lightly.

x

Rip sat cross-legged on the floor of the console room staring at the glowing shard that sat in the small force-field. The Doctor had disappeared into the depths of the TARDIS while Donna was on the phone to her grandfather.

"What are you thinking?" Gideon asked sitting at his side.

Turning to look at her briefly he shrugged, "That I want to be home with you."

"I want that too, Rip," Gideon said softly, "But not until we're sure it is safe for you. You could die for real this time or is that your plan?"

Rip frowned at her, "I don't want to die, Gideon."

"The why do you keep putting yourself in these situations?" she demanded.

He let out a long sigh, "I was the only one who could stop Mallus, even if it was only for a short time. Gideon, I'm not going to stop trying to protect people. The Time Masters may have turned out to be manipulative bastards, but they raised me that way."

"I know," she sighed, "But it was not the Time Masters who made you like this. According to your file even as a child you would protect those weaker than yourself."

Rip gave her a quick smile.

"Can you actually do anything on this ship?" he asked thoughtfully.

Gideon gave him another frown, "No, I cannot and it would be extremely rude of me to even attempt to do so considering the TARDIS is allowing me access to not only you but the Doctor and Miss Noble."

"Just wondering," he mused, bouncing to his feet he checked the power output on the console the Doctor had set up to scan the shard.

"What are you doing, Rip?" Gideon demanded, watching him hit a few controls seeing the field around the shard disappear.

He shrugged, "I want to check something."

"Captain…"

He ignored her and moved closer to it, "I just want to check something."

Rip felt his hand begin to tingle as it began to glow. The tingle began to run up his arms. Something tugged at him and Rip moved closer to the shard.

"Rip, step away," Gideon snapped urgently.

But he couldn't the glow encompassed him as his hand closed around the shard.

x

The light was blinding.

But it didn't burn this time. He floated for forever and no time at all before he slammed into a grated floor.

Hearing the sounds of weapons arming, Rip looked up and found several guns aimed at his head.

"Bollocks."

Continued in Under The Sea - s/13026634/1/Under-The-Sea (Legends Of Tomorrow/SeaQuest Crossover)