Title: Deepest Desire

Summary: Dr. Eggman invented a serum that will make the injected person act upon their deepest desire. He believed that Shadow's was to kill Sonic. Boy, how wrong he was... Sonadow

Disclaimer: I do not own any of the characters from the Sonic the Hedgehog franchise.

Special thanks to chaogardens (from over at AO3) for betaing this chapter.

Chapter 1: In Haze

"Shadow, I'm sure we can talk this out," Sonic said, raising his hands in a gesture of surrender while at the same time backing away from the dark hedgehog, greatly hoping that Shadow wouldn't try to tear him to shreds like Eggman had predicted Shadow would before throwing them into this tiny room.

However, it seemed as if Shadow didn't even understand him anymore as the dark hedgehog made no sign of acknowledging his words, continuing his approach on him with a strange look on his face.

Sonic felt his back hit the wall, his eyes immediately locking onto his drug-affected rival, watching the other's every move intently. He had no way of getting away from Shadow as the room was simply too small—Shadow could very easily catch him if he wanted to.

There were a mere four feet of distance between them now—and Shadow was slowly cutting this distance even shorter.

Soon, not even the small amount of space remained—two hands were placed at either side of his head, effectively trapping him between the wall and the ebony agent, who was now growling. Sonic's ears instinctively flattened against his head at the clear display of hostility, anxiously awaiting Shadow's next move. He didn't want to hurt his friend, but if Shadow attacked...he wouldn't hesitate to fight back.

To Sonic's surprise, the ebony agent made no move to attack him. No. Instead, Shadow just kept looking at him, almost as if he were studying him. Even the aggressive growling had changed to a soft rumble in the dark chest.

Sonic blinked in confusion, his ears perking up again as he looked into his rival's eyes, noticing that they were no longer showing any signs of malice. They were filled with something completely different now—but Sonic couldn't recognize what it was as he had never seen the emotion before.

Shadow's eyes narrowed slightly at the shared eye-contact, though his body language stayed the same otherwise.

"...Shadow?" Sonic called out softly, keeping his voice low as he didn't wish to startle or anger the dark hedgehog in any way.

Sonic was expecting Shadow to respond with something along the lines of 'What?' or just a simple 'Hmm?', which seemed more realistic given his current state, but instead the dark hedgehog did something that Sonic wouldn't have expected him to do even in his wildest dreams.

He kissed him.

However, it wasn't that perfect movie kiss that you could see in a romantic movie, no—this was rough and animalistic.

Sonic made an incomprehensible startled noise at the back of his throat and immediately attempted to pull away from the dark hedgehog—which, however, proved to be impossible with him trapped against the wall like this. Thus he resolved to using his hands that had previously been pressed against his chest to push against Shadow's own chest in an attempt to shove the agent away.

But Shadow refused to move his body despite Sonic's attempts, his low growl of protest making this very clear to the cobalt hero. Instead, the agent's hands left the wall, Shadow briefly pulling away from the kiss to seize hold of his peach wrists and force them above his head, before reconnecting their lips with even more vigor.

Letting out a whimper at the rough treatment, Sonic began to thrash under the other's hold, struggling to twist his wrists free from the iron hold pressing them firmly against the wall. Shadow let out a low growl of irritation at this, the hold at Sonic's wrists tightening even more in warning.

Despite this, the cobalt speedster just continued with his thrashing, not caring if his wrists were going to be horribly bruised the next day because of it. Sonic even gave a few more attempts to twist his head away from the kiss, but seeing as this protest was to no avail, he had to settle for yelling into the lip-lock instead.

"Ghado, stahp—!"

This proved to be a bad move as Shadow immediately used this opportunity to get his tongue past the peach lips. A startled yelp lodged itself in Sonic's throat, the hero having no idea how to react to this uninvited guest in his mouth. However, once Sonic got over his initial shock, he immediately started to fight the intrusion, using his own tongue to try to push the foreign muscle out of his mouth.

But Shadow seemed to have no intention of letting his oral cavity alone, pushing back with even more vigor than him and using the slipperiness of their mixed saliva to his advantage.

A shiver ran up Sonic's spine as he suddenly felt a hand being placed on his hip, not quite sure when Shadow had managed to shift the grip on his wrists to have just one hand holding both of his arms immobile so the agent could run the other up and down his side, the dark hand leaving a strange prickling sensation where it touched him.

Sonic let out a quiet whine, not liking the fact that he was undoubtedly losing the battle and afraid of what would happen if he let it continue.

And so he bit down.

Hard.

As expected, Shadow immediately lurched backwards, a cry of pain mixed with surprise leaving his throat. Seeing it as his chance, Sonic immediately took advantage of this moment of distraction to try to twist free of the other's hold, all the while trying to ignore the taste of Shadow's blood in his mouth as well—he hadn't meant to bite that hard.

However, before he could fully get his hands free, Shadow had managed to pull himself together and tighten the grasp on his wrists again. Sonic gulped audibly when he felt this, wondering if his death would at least be fast.

But then Shadow raised his gaze, the sight striking Sonic speechless as the emotion that he saw in the agent's eyes wasn't rage like he had expected.

The emotion was hurt. And the blue hero just couldn't understand why such an emotion would be in his rival's eyes.

However, Sonic didn't even have the time to think what could've caused it, as a moment later the ebony agent looked away and let go of his wrists completely. Baffled by this occurrence, the hero hesitantly drew his hands back to his sides, unsure of what to think of this gesture when the ebony hedgehog had seemed so adamant about keeping him immobilized just moments before.

But even this train of thought was abandoned soon as the ebony hedgehog's hands shot forward without any warning once again. The first one grabbed his hip, while the other somehow managed to find its way through the half-bristled quills on his back, both pulling him closer to their owner who immediately buried his face into the junction of his shoulder and neck.

Feeling the other's hot breath washing over his neck, Sonic stiffened up immediately, his brain quickly trying to figure out whether fighting or staying calm should be his next move.

Allowing his hands to go free would be an unreasonable decision on Shadow's part if the agent intended to harm him—this way he would be able to defend himself from any possible attacks—so Shadow clearly didn't plan to hurt him...

However, this conclusion was forgotten even faster than it was made—as in the very next moment, Shadow's teeth grazed against Sonic's sensitive throat and the hero's system immediately become flooded with panic at the thought that the dark hedgehog might have just given him a false feeling of safety to get a chance at tearing his throat open. Faster than even his name suggested, Sonic brought his hands up and pressed them against the dark shoulders in a desperate attempt to pull away.

"No, no, no—please!"

However, instead of teeth sinking into his flesh like he had expected, Sonic felt only a gentle nibble on his shoulder, which was not long after followed by a soft kiss to the same spot, the action making his breath hitch. But it wasn't a lone occurrence; his neck was soon showered with soft kisses and nibbles, which didn't feel exactly unpleasant...

More like the opposite...

Sonic actually found himself suppressing a moan of pleasure—which was also exactly the moment his brain ultimately shut down as it just wasn't able to deal with all of the contradicting signals that its owner's body and mind were sending it.

Pull yourself together, Sonic! This guy is freaking harassing you! his inner voice of reason commanded him, knowing that he needed to draw himself out of his daze before it was too late.

In spite of himself, the hero's arms still embraced the dark hedgehog instead of pushing him away.

He's just placating you now—!

Despite its best efforts, the dazed hedgehog still barely registered the voice—or how Shadow's hand slid down over his hip bone and then settled on the outer side of his right thigh.

However, when said leg was pulled upward, the action didn't come unnoticed by Sonic—despite the fact that the ebony agent continued to caress his neck ceaselessly in order to distract him.

And it didn't take a genius to figure out in what kind of direction Shadow was inconspicuously trying to steer their situation.

The cobalt hero took a deep breath to bring some clarity back into his dazed mind, the voice falling silent when it felt him gaining control again. Taking another deep breath, Sonic opened his mouth to speak, hoping his voice would come out strong even though his body didn't feel that way at all at the moment.

"Shadow, stop..."

The dark hedgehog let a strange noise that resembled both a growl and a whine at the same time, clearly not liking the idea of following his demand.

"Shadow, please! This is not the time for this!" Sonic tried, hoping his words would somehow reach whatever remained of the dark agent's rational side—Eggman's serum couldn't possibly have shut it down completely, right? "Eggman could come back to check on us at any moment now! And once he sees that you haven't killed me yet, he'll try to do it himself!"

Sonic wasn't entirely sure if he should take the fact that Shadow had started to growl when hearing this as a good sign or not.

But just then, Shadow finally raised his gaze upwards, his crimson eyes filled with rage that definitely wasn't aimed at him—but on the idea of Dr. Eggman hurting him. The hero let out a deep exhale, relieved that his impromptu plan seemed to be working so far.

Green eyes turned to stare into crimson ones that, alongside rage, were still displaying the strange emotion that he couldn't place. "...We'll continue this after we get out of here. What do you say about that?" he asked, hoping the other would take the bait.

The dark hedgehog tilted his head to the side slightly, a tiny hint of distrust visible in his eyes. "...Promise?"

A little spark of hope ignited in the hero's heart at hearing Shadow speak up—the serum might already be leaving the other's system. Believing that the ebony hedgehog would already be back to his usual grumpy and antisocial self once they were out of here, the hero didn't hesitate to nod.

"Yes, I promise."

This confirmation was all it took for Shadow to begin to attempt to get them out of their little cell.

And to this day, Sonic still wonders how Shadow had managed to spin-dash through a two-foot thick steel door.

O-o-O-o-O

Green eyes surveyed the outside world through the gaps of the shutter of the exhaust vent they had picked as their escape route, checking that among the thick green vegetation of the forest no robots were hiding.

When Sonic figured they truly weren't, he gestured at his ebony companion over his shoulder. "All right, the coast is clear! Let's get moving!" Using his strong legs, Sonic kicked the shutter, the heavy metallic cover falling onto the grass-covered ground with a loud thud.

The cobalt hero jumped out of the vent, from the corner of his eye seeing Shadow do the same just a moment later. Wanting to avoid being possibly spotted by any guard robots that might decide to investigate the source of the noise, Sonic immediately headed into the dense forest, certain that Shadow would follow even without him having to say anything.

Once he reached a small clearing, Sonic skidded to stop, glancing over his shoulder into the forest as he waited for Shadow to catch up with him so they could leave the area together; it was safer to stick together with all the robots surveying the area for possible intruders like them. Plus he wanted to keep an eye on Shadow as he still wasn't one-hundred percent sure if the ebony hedgehog was or wasn't still under the influence of the serum.

It was true that the dark agent had behaved himself during their small trip through the ventilation system—which Sonic believed Shadow's drug-affected self-control wouldn't manage to do—but the agent also hadn't said a word. Shadow had never been a talker like him, but being this quiet was strange even for him.

As the rattling sound of branches being pushed out of the way alerted Sonic of Shadow's arrival, the cobalt speedster immediately shifted his stance, readying himself to break into a run once again. And once the green eyes caught a glimpse of the obsidian fur, Sonic made the first step—only to suddenly find himself lying, with his back flat on the grass and with a certain dark hedgehog atop of him.

Sonic blinked in confusion as he looked up at the other hedgehog, who strangely wasn't displaying any signs of aggression despite having knocked him down so harshly. The dark agent was just watching him with an unreadable expression on his face, that strange emotion—which Sonic still couldn't name no matter how hard he tried—shining in the crimson eyes.

But the agent didn't give him the time to wonder what it could be as, without a warning, Shadow suddenly leaned down and pressed his lips to the side of Sonic's neck while one of the gloved dark hands started to caress the hero's side, causing breath to become stuck in Sonic's throat as well finally make the cobalt speedster realize that the other one was planning to continue what he'd started in the cell.

Unfortunately for Shadow, a few kisses to a neck wasn't enough to make Sonic stop being concerned about the dozens of murderous robots running around, the hero immediately showing this by pushing against the black and white-furred chest with one of his hands while he used the other hand to prop himself up.

"Shads, this isn't the time for this! We're still—"

The rest of Sonic's protest was muffled when tan lips suddenly pressed to his own, the other hedgehog clearly not caring that they were still in the enemy territory and thus could get ambushed at any moment.

Sonic sharply turned his head away, effectively breaking the kiss. "Shadow, stop! We really need to leave!"

Shadow gave a grunt of disgruntlement at this remark, the agent clearly not finding it as something he wanted to do, further confirming this by lowering his head again to nibble at Sonic's neck—to which the hero immediately responded by resuming his pushing. "Shadow, come o—Ohhh!"

Mortification shot through Sonic's veins, red flooding the hero's face at the embarrassing sound he just let slip out. Again. Pressing his lips tightly together to not let out anything similar by accident, Sonic took a deep breath through his nose to calm himself, before focusing back as well as giving a stern look to his ebony rival, who continued to ki-er-abuse his neck.

"Shadow, stop it!" he ordered in what he hoped was a commanding tone. However, when the next thing that happened was his neck getting such a thorough lick that it send a shiver up his spine, Sonic guessed that it hadn't sounded as authoritative as he had meant it to be.

So he tried again. "I'm serious!"

The ebony agent looked up from his neck, those crimson eyes clearly saying that Shadow wasn't going to budge no matter how much he insisted they needed to move.

No. Instead the dark agent lowered his head again and resumed with using those skillful tan lips on his neck, slowly making him lose his resolve while at the same time making his body feel more and more like a jelly by massaging his tense muscles in such a wonderful way that he didn't even notice when he was softly pushed onto the ground again.

Chaos, how could it feel so good...?

"Shadow...stop..." Sonic managed to get out despite the fact that his thoughts had been turned into a jumbled mess of nonsense by the dark hedgehog's ministrations, the hero, in the corner of his now-hazy mind, still realizing they were in a highly dangerous location.

However, even this little corner of the hero's mind was forgotten when Shadow moved his mouth from Sonic's neck back to his lips, capturing them in a gentle kiss that made Sonic's mind fully drift away from the world and into the blissful daze induced by the dark hedgehog.

However, this didn't last long—as in the next moment Sonic could feel a knee pressing against his crotch, this area of his body so unused to being touched that it immediately made him snap out of his daze with a surprised squeak.

Which wasn't exactly a manly reaction, but he guessed the fact that nobody had ever breached his personal bubble in such way before justified reacting this way.

—that, however, still didn't mean he hadn't felt completely embarrassed about it when he heard that there was somebody else beside them.

"Oh, my, I didn't know you two were into public sex."

And it was at that same moment that Sonic recalled that upon their arrival to the Egghead's base Shadow had told him that a certain bat should have been somewhere in the building as well.

"R-Rouge?" Sonic blurted out in surprise once Shadow raised his head to look at the newcomer, the cobalt hero's cheeks turning scarlet as his brain finally processed what actually Rouge had said and in what kind of compromising position they were, while Shadow's face just kept its original color, the dark agent obviously too busy with glaring at the bat for interrupting them to feel embarrassed.

With a small smirk playing on her lips, the female agent gave the duo a raised eye-ridge from her position high in the crown of a nearby tree. "So this is why you two weren't responding to my calls? And for a moment I thought you might be in trouble."

The hero wanted to retort that they had been in trouble (and he still kind of was), but this thought was forgotten the moment that he realized he had no idea what 'calls' was Rouge speaking about.

And just then, from the corner of his eyes, he noticed that a small part of the GUN communicator on Shadow's wrist was repeatedly flashing green and red, as if it were trying to get their attention, and only then Sonic recalled that he had seen Shadow turning the communicator off at one point during their stealth mission.

"Well, I guess I should take my leave then. You're obviously occupied, somebody still needs to keep an eye on Doctor and I'm pretty sure that I'll burst in flames if Shadow continues to give me that death glare," Rouge joked as she spread her wings, bending her knees to spring herself into the air—and almost falling from the branch in surprise when Sonic shouted in panic at the same moment.

"Rouge, wait!"

Shadow immediately turned his glare from Rouge to Sonic, the dark gloved fingers harshly digging into Sonic's sides, the ebony agent clearly not appreciating his decision of telling the bat to stay. However, Sonic just ignored both actions and focused fully on Rouge as at the moment she was the only person that could stop him and Shadow from doing something they would both regret later—as he didn't think he would resist Shadow's charms if the dark agent tried to continue and Shadow definitely didn't look like he planned to do anything but that.

"Shadow's drugged," the cobalt hero cut to the chase, needing Rouge to understand the seriousness of the situation. "Eggman gave him some serum that is making him behave all—er—clingy, " he explained, yelping when Shadow choose that exact same moment to wrap his arms around his blue and peach form and then roll them both over into a sitting position, the blue hero suddenly finding himself straddling the agent's lap with dark arms wrapped around him in a possessive hold, the ebony agent now glaring at the bat over his shoulder with even bigger intensity than before.

"Very clingy, indeed," Rouge commented with a small chuckle as she jumped down from the branch, slowing her descend by flapping her wings a few times; and once on the solid ground, she walked over to the hedgehog duo, her smirk stretching wide when she saw how her ebony co-worker tightened his hold even more. "Need a help with getting him off?"

"Definitely," Sonic replied as a faint blush started to form on his cheeks due to the proximity with the dark agent, the hero burying his flushed face into his rival's shoulder. "He doesn't want to listen to me," he added as an explanation once he heard the bat approach them, the firm grip that the other hedgehog had on his body not allowing him to turn around.

Rouge didn't give any sign of acknowledgement of his words, her attention obviously already on her colleague. "Alright, sunshine, even thought I'm happy to see that you've decided to change your mind about befriending people," she said, a hint of amusement in her voice, "I think you're getting way too friendly with Sonic here. You should probably give him some space."

Shadow growled as he pressed Sonic even closer to his own body, leaving practically no space between them.

Sonic gulped, now able to feel a move of every muscle under Shadow's dark pelt due to the closeness—and this was definitely way too close for his liking. "Er, Rouge—"

"I'm working on it!" the female agent snapped before he could even finish his complaint, the bat obviously not happy that her first attempt on persuasion hadn't worked. She watched the defiant hedgehog for a moment longer, trying to come up with a plan that would force Shadow to let go of Sonic on his own—as she herself definitely didn't have enough physical strength to pry the hero out of his grasp.

And just then her ears caught a sound of something which made a victorious grin appear on her face as it was ideal for what she needed right now. With a quick "Be right back!" she took off and disappeared somewhere in the forest, Sonic immediately feeling his stomach drop in apprehension at hearing her leave.

And this feeling proved to be an appropriate one as Rouge returned only a few seconds later—because this time it was with three giant robots chasing right after her.

[Last edited: 2018-07-01]