This is an Omegaverse! I know, I know, there aren't many and this is my first one in this fandom. I have no idea when this happens, it just sort of came to my brain. This is Alpha!Danny and Omega!Steve, so there's gonna be mpreg, relationship development and trouble.

I do not own Hawaii Five-0, it belongs to CBS.

Chapter One

Danny impatiently rang the doorbell again, and then tapped his foot, rolling his eyes. He pulled out his phone and pressed the call button, lifting the phone to his ear.

"Come on, Steven. What the hell?" There was no answer so Danny sighed, trying the doorbell again.

Steve hadn't shown up to work, which was unusual since he showed up before anybody else, and there were no calls that he called in sick. So Danny volunteered to go check on him, which led him here. Steve wasn't answering the door or his phone so it caused him to be incredibly concerned. Sure, Steve had dodged his calls before, but this was unusual.

"Steve, open up!" He knocked, and the door creaked open. Danny stiffened. Steve never left his door unlocked. Danny pulled out his gun, slowly pushing in the door and stepping in. He cleared the living room and then stepped into the office area, cleared that and then stepped into the kitchen. The stove was still warm and there was a plate in the sink but no signs of Steve. There weren't any signs of struggle or a fight, so… Upstairs?

Danny slowly started to ascend the stairs.

"Steve?" He called. "Come on, buddy. I don't like this." He noticed that Steve's door was slightly open, and Danny was starting to get worried. Don't be dead. Danny held his breath and opened it to see Steve lying on the ground, fully dressed but unconscious.

"Steve!" He quickly ran up, putting his gun away and kneeling down, feeling his neck. He was alive and his pulse was insanely strong.

"Steve, come on, wake up." He shook him gently before pulling out his phone to dial for an ambulance. Then he noticed the pill bottle. It was capped, but it was empty. He narrowed his eyes before walking over, picking it up. Steve was not a drug addict and he knew for a fact he wouldn't overdose on anything. He turned it over, reading the label.

Heat suppressants

Medium Dose

For Omega: Steve McGarrett

Danny stared at the bottle. Steve was an Omega? Steve, the all-powerful ninja SEAL that seemed invincible and gave off the vibe that he was an Alpha, an Omega? Sure, people mistakened Danny for an Omega when he was actually an Alpha, but still…

Steve groaned and Danny quickly went over to him.

"Steve, hey, you okay?" Steve panted, gripping his knee.

"D-Danny… You need to get out of here."

"What? No! I'm not leaving you-"

And then the smell hit him.

The smell was a mix of vanilla and mint, and was so insanely strong Danny immediately knew it was Steve's pheromones. The scent was intoxicating, and Danny's senses went out of wack.

Danny quickly covered his nose and started to breathe out of his mouth, but it was too late. His vision swam and the only thing that he thought of doing was grabbing Steve and stripping him until he was naked and-

Steve cried out and curled up, his cargo pants staining.

"S-Steve…" Danny said softly. "I know that you're in heat, and I know you will probably want to be left alone, but I know that I will end up here again if I leave, so I can't leave you alone like this." Steve stared at him, his cheeks flushed bright red, sweat glistening on his face. Then he looked down.

And nodded.

At the nod, Danny completely lost all control.

Danny grabbed Steve, throwing him on the bed and causing Steve's breaths to quicken. Danny quickly made work of his boots and pants, shoving them on the floor and away, then slamming his lips to Steve's. Of course, the blond always thought that Steve was attractive, but he would have never imagined kissing or stripping his best friend.

Danny's hands slid all over Steve's body, down his sides and laying his hands on his hips. Danny bit Steve's lip then pulled away, keeping his lip in between his teeth, staring into his eyes. Steve's eyes were filled with lust and hunger and need, and Danny felt his dick harden by that look.

"You know, babe…" Danny murmured against Steve's ear, planting a kiss against his ear. "You have a really hot body…" Steve moaned as Danny bit his ear, heat surging through his body.

"D-Danny…" Danny groaned, spreading his legs and pressing their hips together. Steve cried out at the feeling of the contact and bucked his hips against Danny's. Danny grinned at the reaction and laid his lips on his neck, sliding his hands up his shirt, his fingers tickling his abs. Then in one swift motion the shirt was off. Steve watched as Danny unbuckled his belt, before sitting up and doing it for him. Danny looked at him in surprise which turned into shock as Steve pulled them down along with his boxers. Danny's rock hard length popped up, causing Steve to stare at it.

"I-I didn't know you were so big, Danny..." He said as he wrapped his hand around his cock. Danny groaned.

"Well, Steven, I didn't think it was necessary. I didn't even know you were an Omega..." Steve shakily smiled before he squeezed his legs together, panting softly, before licking the head. Danny moaned, shifting his weight. Steve took a breath before taking in the head, then half, then almost to the base. Danny let out a loud moan, tilting his head back in pleasure. Without thinking, he grabbed a tuff of Steve's hair, the soft, not really gelled hair, and then wrapped his hands around his head, shoving his head down all the way. Steve's eyes widened, and he grabbed at Danny's hips, trying to push away.

"Shh, babe, just relax..." Danny moaned out. Steve took in consideration before his body relaxed and he allowed Danny to thrust in and out of his mouth. Steve's throat felt so damn good... Hot, wet and slick... Danny couldn't wait until he was inside him...

"S-Steve! I'm close!" Danny cried, before he slammed Steve's mouth all the way down to the base, then released his load down Steve's throat. Steve trembled, looking like a needy slut as he took the white substance down his throat. Danny panted, his shivers settling down as he came down from his high. Steve pulled away, coughing a bit and holding his throat.

"Shit, Steve... You okay?" Steve nodded a bit before they locked eyes, and Danny gently kissed him. It was softer, sweeter and more gentle than the last few kisses, but Danny pushed Steve back and begin to devour his lips again. During this, Danny kicked off his shoes and pants and shooed them onto the floor, lifting Steve's legs and running his hands up his legs. Steve ran his fingers through Danny's hair, trying to push himself into Danny's body even more. They broke for a second and Steve took the opportunity to speak.

"I-I don't have any condoms... J-Just lube..." Danny winced. No condoms meant higher chance that Steve could get pregnant... Danny sighed.

"I think your slick will do..." Danny said... "As for the condom-"

"Knot me." Danny froze, looking at Steve. Steve's blue eyes stared at him with need and lust and Danny felt his arousal grow even more.

"What?"

"I-I want you to tie with me..." Danny shook his head.

"Steve, you could get pregnant." Steve opened his mouth to reply when his back arched and he cried out. Another wave of pheromones hit Danny and Danny's senses went out of control.

"I-I don't care if I get pregnant! Just hurry up!" Danny rid him of his underwear and lifted his legs, causing Steve's eyes to widen. Danny lined up with Steve's entrance, the puckered hole slightly quivering. Steve's dick was hard and already leaking with pre-cum, his entrance covered in clear slick. Danny took a deep inhale of Steve's pheromones and pushed in.

Steve's cries of pleasure was the only thing that filled the room.

Danny woke up to sniff in apple scented shampoo and lifted his head, grimacing at the bright light. He blinked and looked around... He was definitely not in his room or a hotel room and-

Oh, dear God.

Danny slowly moved his eyes down to the body laying next to him, Steve's breaths gentle and even. He was covered with a sheet and blanket and Danny was wearing boxers so that meant...

The previous night flashed in his mind. Steve's body writhing underneath him, his weight on top of him, against the wall, in the bathroom... Oh, dear God.

Danny noticed the bite marks all over Steve's neck, throat, shoulders and even back. Bruises were around his wrists and peaked out from underneath the sheet on his hips. At least Steve was sleeping...

Danny's phone begin to ring and he grabbed it off the nightstand and immediately answered, really hoping it wasn't important.

"Detective Williams." He said, his voice hoarse.

"Hey, Danny. We got a body. What's up with you? You didn't come back to HQ after you went to Steve's, everything okay?" Chin asked. Of course, they were more worried about their boss than the dead guy, typical.

"Yeah, yeah." Danny said quietly. "Steve's sick with the flu. Really bad throwing up and stuff. I stayed here to heal him." He slowly got out of bed, Steve moaning and curling up.

"Oh, okay. Well, hurry up. We're on the way to the scene."

"Right, right." Danny said, pulling on his pants. "See you there." He hung up, laying the phone on the bed, grabbing his shirt and starting to button it up when Steve woke up.

"D-Danno...?" Danny froze when he bent down for his holster and badge and stood up straight, see the angelic and innocent look on Steve's face. He was really regretting leaving him like this, but he had no choice.

"Hey, just... Sleep, okay? There's a case, but I told them you are sick with the flu, so don't bother coming in. If I see you there I'm shoving you in my car and driving you back here." Steve stared at him before he nodded slowly, then fell down like something hit him.

"No goodbye kiss?" Steve asked, almost mockingly, but at the same time like he wanted one. Danny finished with his shirt and walked around, leaning down, brushing their noses together before laying a gentle kiss on Steve's lips.

"I will see you tonight..." Danny muttered, resulting in a shiver from Steve.

"Okay..." He mumbled back. He was totally out of character, the normal hostile demeanor seemingly vanished from the day before yesterday when he was bossing everyone around. Now he was like a sleepy wife who just woke up and was cranky.

"Bye."

"Bye..."

Of course, Danny returned and Steve's heat lasted for about six more days, so... Yeah, they had the time of their lives.

So first chapter is done. I didn't go into total detail because of some problems I've had in the past, but it pretty much sums everything up, right? Next chapter is coming soon, so stay tuned!