Genre: Alternate Universe - Sentinels and Guides

Pairing: Steve McGarrett/Danny Williams

Spoilers/Warnings: Graphic depictions of violence, torture. This story begins around Season 2 episode 20 (where Steve leaves to go to Japan) and then goes fully AU once we get to the end of the season. I have seen episodes of the Sentinel, but this is my take on it as a concept taken from the show as well as fanon.

Originally published (on ao3): March 2013

Author's note: I love the Sentinel/Guide trope in fics for Hawaii 5-0. Steve and Danny seem to be a perfect fit for me in that world. I've read fabulous fics already for Sentinel!Steve and Guide!Danny and how they met, and I don't want to mess with the perfection out there so I decided I'd rather pick up the storyline further in, which also gives me the chance to use my favorite Five-0 villain.

Partner, I'm sorry I couldn't be there in person to tell you this, but I need to find Joe White. I think he lied to me about the identity of Shelburne, and I need to get the truth. Shelburne is the real reason my father was murdered and maybe even my mother, but until I get some answers, I can't do this job right. Danno, I need you to hold down the fort for a while, I'll be in touch. Mahalo.

Danny read the letter and mumbled a 'Mahalo' himself in disbelief at what he was reading.

He had wondered why Steve had been so 'off' the day before. Evasive and distracted despite Danny's best efforts to engage him in any kind of conversation.

In the afternoon, Steve had taken Danny home, he'd taken him apart, slowly, and strengthened the imprint he had on his Guide. Yet Danny had put it down to jealousy after he had been seen by another Sentinel in the coffee shop that morning. Neither man had missed it, especially since the other Sentinel had a sleazy look to him, with his dark hair slicked back with too much product and a far too bright Aloha shirt covering a rather well-muscled chest. As a Sentinel, Steve had a possessive streak to rival his protective one and where Danny was concerned it ratcheted up to eleven. Danny had become used to it over the last few years, but with them being paired up so late on in their development, it was like Steve was making up for lost time. Danny would also bet his last paycheck that Steve would be like this, Sentinel or not.

He had been convinced that Steve had just wanted to reiterate their bond so anyone with any Sentinel senses would know to back off. He'd even teased him about it.

Now, Danny looked back on the previous day with new eyes.

Steve had already decided he was leaving without Danny. He'd focused the imprint because he knew he'd be away for a while. The only worry was how long. And on top of that, what the hell had Steve been thinking, leaving without him? He'd just thought Steve had left in the truck earlier that morning to get in to the office and do paperwork, but clearly he'd left to get in to leave this note and then run off to God knows where, to do God knows what with God only knew who. Stupid Sentinels and their protective nature.

He had no time to think about it as Kamekona burst through his door, asking for help locating his missing shrimp truck. Then the trash-man case had taken all of Danny's attention. There were too many times during the day that Danny found himself waiting for Steve to loom over him. At one point, he even went to touch Chin's shoulder as he looked over evidence, automatically reaching out to ground a Sentinel who wasn't even there.

He kept catching himself wanting to guide over the day, but he couldn't deny his nature either. And he wanted Steve to be there to calm him down when he got short-tempered or overly sensitive.

Late on in the day, after the case was solved, the Governor had pulled him into his office to talk about how the 5-0 task force would run with a Guide at the helm rather than a Sentinel; as if Danny wasn't a trained Police Detective and was just a glorified babysitter to an overgrown 5 year old who liked things that go bang. Luckily the collar for the trash-man so quickly had eased the man's mind, and Danny was to be left alone to do his job, just like Steve had been.

Besides, Steve would be back.

As he sat by the beach with Chin at the end of the day, he reasoned Steve's disappearance away the best he could. He'd left on his own, without backup and without a Guide to protect them. He left them behind so they wouldn't get hurt, and he knew he was right because he knew how Steve's mind worked. What he didn't add was just how idiotic Steve was being in thinking like that, but he knew Chin could read it in his eyes without him having to say it out loud.

Chin and Kono knew Steve and Danny the best. They may not have any clue what went down in private, but they knew the working relationship and they understood the dynamics of them as friends, partners; as Sentinel and Guide.

"To leave you behind, Danny," Chin reached out and placed a hand on Danny's arm. "It must be pretty major to leave his Guide behind."

Danny nodded, "And when he gets in touch he's going to hear about it."

"I know, brah. Not to put you down or anything, but until 2 years ago he was a Navy SEAL Sentinel without a Guide and he was fine. He's going to come back fine again."

"Two years ago, before he met me, he was an idiot skating by without a permanent Guide. He was lucky I agreed to this shit in the first place." Danny grumbled; his frustration coming out in his tone. "I took pity on him when he looked at me like a puppy at the pound. And in the same vein, he pretty much told me he'd die if I didn't help him, and what're you supposed to do when someone tells you that?"

"Maybe he has someone with him now that he used in his SEAL days."

Danny acknowledged then ignored the sting of jealousy that Chin's words evoked, letting his constant worry take over again in its place. "If he zones out there and it's bad… a temp Guide may not work. In fact, a temp probably wouldn't work because as it is, it was unsuspecting little old me that brought him out of that last bad one when his dad died. It's only been my voice, my scent, my touch that has grounded him since so why, in that thick headed skull of his, would he think a temp Guide would be any real help to him now?"

Chin didn't get the chance to answer as Kamekona once more got in the way before Kono arrived with his truck.

Danny hadn't been sleeping right without Steve there. Something in his head was missing.

Something was wrong.

Steve may be the Sentinel and have the enhanced senses but Danny's sense of well-being was completely off without Steve. He'd never experienced this before, but then he'd never been apart from Steve for more than a day since they'd met. Steve had insinuated himself into Danny's life like a dog with a chew toy and he just refused to let go. It had been endearing at first but felt over-bearing quickly so Danny had kept his apartment in a last bid to have a sanctuary away from everything; at least sometimes. His need to know that he still had his own life, that it hadn't been taken over by someone else, was insistent.

He was the one whom other people depended on. He had Grace and he was used to providing for her. To have Steve waltz in and become territorial with Danny so fast was too much to take. But it hadn't lasted long, and by the end of the year, when Danny was given no choice but to move out from where he was, Steve had corralled him into his house and he'd been there ever since.

Steve had given perfectly valid reasoning. Danny stayed over plenty as it was considering they were sleeping together. Even when Danny was at his apartment they still had their phones to tether themselves to each other, so it was logical that they gave in and lived together properly. But Danny hadn't figured that the link between them was as substantial as it appeared to be now. He'd never known because they were comfortable living in each others' pockets, with a pretty regular routine for two cops who could get pulled onto a case at any time of night or day.

He shook his head as he sat at the table. It was like there was a string holding them to each other, and it had been stretched way too taut with Steve being so far away and them having had no contact at all. And he had this constant, building, low thrum of a headache at the back of his head.

After that first day, Danny had expected a phone call. He may not have been with Steve but surely the man needed to talk to Danny? Even professionally… SEAL to Cop or Sentinel to Guide it didn't really matter to him. Instead, the only phone call he received that night had been from the Guide Center, concerned about him without Steve there. The Governor had apparently called it in that Steve had left, asking for advice on whether Danny would be okay to do his job – the meeting they'd had together that day clearly not enough to persuade the man that Danny was perfectly fine and that he wasn't just going to faint without Steve there. Or that wherever Steve was, he wouldn't zone out and that would be it. He had been told by the Center that if he was having difficulty, or if Steve didn't return soon, they would send someone out to assess and help him.

Even if he was having difficulty, which he maintained he wasn't despite the headache and lack of sleep, he had no plans to call that damned Center. He didn't have a huge amount of faith in them as it was; misdiagnosing him as a child to be only slightly empathic and not a Guide like his mother and one of his sisters, let alone a high-level Guide like his Aunt. Because of them, he'd never been introduced to Steve sooner and who knows what would have been different if that had happened?

And yet, he couldn't regret the life he had. Sure something had been missing and Rachel hadn't been able to fill that void. And he wouldn't give up Grace for anything - he loved his little girl too much for that. But it angered him that Steve could have suffered if not for them actually happening upon each other like they did.

It was his own fault too, though. Over the years he suspected something was wrong, considering the other Sentinels he'd met that had taken interest in him. But he'd always put them in their place, told them they were wrong, that he wasn't a Guide… that asking if he was, was a bad pick up line and besides, he was a cop and he'd bust their balls if they tried anything.

Apart from his uncle, he'd never met a five sense Sentinel before Steve, only low level ones. The most advanced he'd met was a three sense fire-fighter who worked with his dad. He'd even dated the guy a little before meeting Rachel but they both came to the conclusion that they didn't fit and the guy was really a romantic looking for his true Guide so it wasn't fair to either of them to continue seeing each other.

He rubbed the back of his head, the pain not dulled by the Tylenol he'd taken and he just wanted some decent sleep.

Dammit, he didn't want to call in help from the Center. They'd mother-hen him like they always did, as if trying to make up for not bringing him in as a child and giving him proper training for this life he found himself in now. And then they'd probably take him away 'for his own safety' which would mean leaving Grace for a while and he wouldn't do that. He wouldn't leave her and he wouldn't worry her. It was bad enough when he had to explain that Uncle Steve was working away from home right now, but would be back before she knew it.

He sighed then went back to looking at everything he had laid out from the Champ box. If he just knew where Steve was…

He unfolded the map. It had Shelburne listed on it and it wasn't Steve's handwriting. A map of Japan. If Steve was there then he really had no excuse for not calling. Danny was very well aware that they had phones in Japan. They had a lot of technology. There was no excuse because it wasn't like Steve needed to send a Sherpa on a camel over desert and mountains for a week to get a quick note to Danny that said 'I'm fine' on it.

"You know, you could look at that stuff all night and not get any closer to figuring it out."

Danny looked up in shock to find Chin standing just a few feet behind him. His head must be worse than he thought if he didn't realize Chin had come in the door.

"I think I may have figured out where he went." He handed the map to Chin.

"Never seen this before," Chin started, unfolding it. "Shelburne."

"That is definitely not his handwriting."

"No, it's his father's. Alright, so what? You're going off to Japan too?" Chin's question was logical. Would Danny go off hunting up his Sentinel? It was the one thing Danny had been afraid of when becoming Steve's Guide – he'd end up following the guy around the world on a SEAL mission rather than staying put and being right where he needed to be for Grace. North Korea had been bad enough as it was.

"No, I am not going off to Japan, I am going to stay here and do my job." It killed him to say it. He had been seriously considering it but his instinct to stay for Grace was one he had to listen to. And he was well aware that Grace was likely the very reason Steve had left without him. He'd been mad at the man for a week now. He'd thought of every reason Steve would throw out for leaving him and it always came back to Grace, which made Danny feel awful about being mad at Steve because the man was thinking of Danny's safety in this whole thing, wanting him to be there for his daughter like he'd always said he would be. Sometimes he hated when Steve actually listened to him. "Leaving and not telling anyone where I'm going is not my style," he added.

"I know," Chin nodded.

"He leaves me a note, says he's going after Shelburne, disappears for a week and he doesn't call and doesn't say 'I'm alive' or 'everything's okay'…"

"Steve believes Shelburne is the answer to a lot of questions, including why his father was murdered."

"His father is dead. And finding Shelburne is not going to change that, I promise you that. And dealing with his father's murder on his own has never ended well for him, hence why I'm here in the first place…"

Chin nodded but the conversation halted with a call from the Governor that Danny answered with only a little bit of distaste.

Danny was thankful in many ways to the smallpox case. If anything it really did take his mind off having Steve missing, even if his headache never went away and he certainly didn't get any sleep while investigating.

Chin had been there at his back the whole time, keeping an eye on him. The worry was evident on the native Hawaiian's face as he watched Danny go through the day. The introduction of the NCIS agents had made the dynamics different, to say the least, but Chin had been right there beside Danny when they realized that Agent Hanna was a low level Sentinel with advanced sight and the agent with him wasn't his Guide.

Sam knew Steve well, he also knew that Danny was Steve's Guide. The other man was confused to not find Steve plastered to Danny's side, but Danny felt no obligation to explain anything. Sam's partner, Agent Callen, wasn't his bonded Guide - a fact that had thrown Danny. He'd assumed with them working closely that he would be and they acted very much like they were, but Sam's wife was his Guide and they didn't work together anymore as she had retired in order to have kids. It made sense to Danny though, as that's what his mother had done. While at work, G helped where he could but apparently there was a low-level un-bonded Guide on the team back in LA, or so Sam told Danny after they ran Comescu's car off the road at Sand Island.

"Fat lot of good that's going to do if you zone while over here."

"I knew coming in that you were McGarrett's Guide. Figured if I got into trouble you could temp for me."

"I barely know how to help Steve most of the time, and you expect me to be able to temp for you. Are you nuts?"

"We'll cross that bridge when we come to it."

"If, if we come to it. And I gotta tell ya, I'm sensing a Navy SEAL colored pattern here. Not just back seat drivers, no, but you just assume the team around you will follow your stupid asses into danger and everything will be okay in the end."

Sam turned and looked earnestly at Danny, while riding back to the warehouse in the Camaro. "McGarrett trusts your abilities. If he does, then I do too."

"That's what I just said, isn't it?"

Sam shook his head with a rueful smile as they pulled up. The conversation never came around again. Sam had been steady when using his ability and they'd closed the case. They were happily bantering over the car's name when Kono called to say the case wasn't over after all.

Danny had to get on a plane to LA, and that string that was wound tightly in his head got worse. Flying back to the mainland, putting 5 more hours and too many more miles between himself and Steve increased the pain. He just wanted that string to relax, even a little. Maybe make it a bit more elastic so it wasn't wound so tight, but no such luck.

He pulled out a tub of extra-strength Excedrin and hoped to hell it would work as he dry swallowed them while sitting on the plane.

"You okay?" Sam asked, while Chin looked on concerned.

"Yeah, I'm fine. I'm surrounded by people who have no reservations about jumping out of a plane, on purpose, no less, and I'm heading into a possible outbreak of smallpox. I'm just peachy, thanks for asking."

"How long has Steve been gone?" Sam was starting to catch on, Danny could tell in the way he looked at him. The guy had been away from his wife for no more than a day, there was no way he'd know how it felt, and that was only if Sentinels felt things like Guides did. As it was, Danny was only assuming this was a feeling all Guides got when separated from their Sentinels and it wasn't just some sort of placebo thing from him missing Steve in a perfectly normal way. The Guides in his family had never said anything, but then, he'd never mentioned anything himself to Chin or Kono this past week either.

"About a week," Chin answered, while Danny simultaneously answered with, "I wasn't keeping track."

Sam sent him a look that said he wasn't kidding anyone. "Bad headache?"

Danny cleared his throat. "I'm fine."

"I feel for you, buddy," Sam said as the plane began its final descent.

If he didn't have a headache before, he would after meeting Deeks and getting that smallpox jab. But he'd enjoyed spending a little time with Kensi. He'd never really been able to sit down with a Guide who did the same kind of job he did. Okay, he'd met other Guide cops, but Kensi had to wrangle a Navy SEAL occasionally and he was open to having a frank discussion with her about dealing with him. As well as how she dealt with Deeks, on a daily basis. She already told him about Deeks' armpit theory and he had pointed out to her that he was only jealous because she had another Guide to talk to and they had something in common. He had tried to steer her onto safer topics of conversation, trying his best to ignore the elephant in the room – Danny was here with Chin partnering him, and not his Sentinel, who had disappeared on them. Kensi knew Steve, had met him before though she'd not met Danny at the time. Joe White had spoken highly of her and Steve had met with her to discuss Shelburne stuff. It was always going to come up for discussion.

Thankfully Deeks had distracted them and Danny had been able to forget about his headache and his hunger and lack of sleep, for just a few minutes. Then they had to go save the world.

The come down from that adrenaline rush had left him exhausted again. He was surprised they were still on their feet and now he just wanted to go home. He didn't even want the shower or the beer. At least getting on a plane back to Honolulu meant he was heading back in Steve's direction.

"Fortunately your talent for Police work far exceeds your gift for discourse, Detective, though I am willing to put that down to your separation from your Sentinel." She paused, looking at him strangely, sizing him up yet again in the way that creeped him out. "On behalf of NCIS I would like to thank you both for your help." She shook Chin's hand then turned to Danny. "I'm sure that headache of yours will begin to ease soon."

"I didn't cause it," Deeks put in.

"It's rare, but it can happen during separations. Most unpleasant. I once knew a Guide whose Sentinel had been injured in an embassy bombing. She lost track of him, found out a week later that her Sentinel was lying in a Turkish hospital with a concussion and a broken leg. I drove the Guide over three different borders to reunite them."

"Three borders, you say." Danny said, trying to be polite, yet also intrigued by the story.

"Not that the border guards knew anything about it." She stopped the story and Danny looked at the others who showed no sign that anything was out of the ordinary.

His impatience drove him to blurt out, "So what happened?"

She looked at him like she would placate a small child. "I don't know. I dropped her off and got out of there. I wasn't going to stick around for a Sentinel reuniting with his Guide after that length of time."

"What, what do you mean?" He asked wearily.

She patted his arm. "I'm sure you'll find out when yours returns."

She walked off, leaving the others smirking at him.

"Sam?"

"Never experienced prolonged separation," he replied, holding his hands up.

"Kensi?"

"Un-bonded," she gestured to herself.

He looked at Chin, hoping his friendly face might show some sympathy or concern but all he saw was amusement. "I just want to know if I'm in danger of bodily harm here, is that too much to ask?"

Chin reached out to Danny's shoulder, "Brah, this is McGarrett we're talking about. Of course you are." Chin turned to the others. "Aloha," he said as he walked off.

Danny trailed after him after waving a quick goodbye, "Hold up, you don't know what happens when we, when we, you know…"

"I know Steve, and I know you, and I can guess the rest." Chin laughed, " Kono? Well she's got bets on the kinky stuff."

"Kinky, what the hell? It's not… Steve just likes…"

Chin put his fingers in his ears, "too much information…"