The facility was heavily armed with security drones who patrolled each sector constantly, although Shadow could take them out easily and access the computer mainframe to find the layout of the station, he couldn't risk sounding the alarms before securing Sonic.

So instead he searched each level of the Death Egg, one by one. Hugging the walls to avoid all survelliance in each area, hiding in the darkness as the robot patrols passed by, and utilizing the crawl spaces as often as possible. 
It was taking much longer than anticipated to comb every inch of the facility, but he had to be vigilant. If Eggman or Infinite discovered his presence, they could easily move the blue hedgehog before Shadow could get to him. 

Aside from the humming sounds of machines, the station was eerily quiet, almost deafening. Then, he heard a screeching cry echo throughout the sector, a scream of agony coated in desperation and fatigue. "Sonic?!" he exclaimed to himself, but he had never heard him make such a sound before, and that thought alone made a lump swell up in his throat. He quickly followed the bonechilling cries as they vibrated off the metal walls until they led him to the maximum security block. Despite the long hallway, there was only one cell in this section, reserved for a single prisoner. In order to maintain stealth, he entered the ventilation shaft and quietly proceeded to the cell at the end.

"STOP...P-PLEASE!!! IT HURTS!!!" he heard crying out.

Shadow readied himself to leap into action, but was caught in a state of shock at what he was witnessing. Peering down through the vent, he saw Sonic's arms were bound tightly behind him while the profane jackal dug his claws into his chest, which were leaking streams of red. Infinite cackled in-between his pleasurable grunts as he penetrated his victim with a fast rhythmn and equally strong force. He was very zealous today and eager to make his pet earn another perfect score in his 'education'.

"Are you enjoying the show?" he snarked as he pressed his knot within him once again, the cries and screams blending together. 

Immediately, Shadow thought the jackal was talking to him and backed away from the vent; however, that wasn't the case at all. What was happening right now had nothing to do with Shadow's presence, but rather another session of Sonic's 'education'. 

"Come now, you have a front row seat. Let's hear that scream again," he mused as he gently lifted his mask enough for his jaw to be exposed. Licking some of the blood from Sonic's chest made him salivate and thirst for more.
With intense fervor, he clamped his teeth into the soft tissue of his prey.

Sonic let out one last unbearable cry as he writhed in his binds, unable to break away from his tormentor. It was then that Shadow knew what his enemy was really doing. Through the flooding tears in his swollen eyes, he saw the unmistakeable resonance of the Phantom Ruby's influence glisten in Sonic's eyes. The poor hero was caught in the gem's illusion and was being forced to watch everything being done to him. Whether or not that's all he saw is unclear, but him being connected to Infinite's power complicated matters.
If Shadow ambushed his target while they were connected, the resulting backlash could leave serious psychic damage. And if the time to attack was ill-timed, then the jackal could just as easily trap him within the ruby's power as well. 

As much as it pained him, he had to wait for the events to play out for the right moment to strike, and each moment that strained his patience added more fuel to his rage.

Meanwhile, Infinite gave into his natural instincts and relished in the meal of his victim's breast.
"Hmmm...", he resounded as he released his bite, "Delicious."

He leered amusingly as the hedgehog's whole body trembled while he begged with a broken voice, "P-Please...m-master....no more today...please."

Infinite leaned down near his face and grinned menacingly as he whispered in his ear, "This is only the beginning of today's lesson. A special one I've made just for you."

As exhausted as Sonic was, he still trembled in fear as the jackal resumed his position and began thrusting even harder and faster than before, his hard equipment rupturing the hedgehog's insides until blood began coating the cylinder and squishing out on each thrust. It was bigger and harder than ever before, an augmentation of the ruby. Although this wasn't the first time he pushed his prisoner's internal structure past its limit, he was finding new methods of doing so.

"I'm going to continue to expand its size and I want you to beg for more," he cooed while, true to his words, the energy of the ruby gradually increased the width of his cock.

Sonic sobbed and moaned as his anus was being ripped apart. He could feel it grinding against his pelvis while the flesh gave to the unstoppable, "P-Please....s-stop....it's....it's killing me....."

Infinite gripped Sonic's throat with a choking lock, making his gasp and grunt for what tiny bit of air he was afforded. The mercenary relished in seeing those precious lips turn purple as he squeezed harder while providing the objective of today's lesson, "Life and death have no hold on you anymore. You won't die until I am done with you, and there's so much more I have planned, so much more for you to learn."

Gurgling yelps escaped the hedgehog, whose eyes began to roll back. The jackal didn't relent in his lower motions, which he then began to sway from side to side in conjunction with inward and outward. He was caught in a state of ecstasy by the reaction of his victim's body, the quivering, restricting muscles all tensing as his oxygen was cut off. The ruby's power exhilarated him far more than his own carnal urges to the point he had to give into his unrestrained arousal, and in releasing his grip, he quickly sank his teeth into Sonic's other breast while ejaculating a hot stream into his pet. 

It was then that Shadow saw the red light seemingly vanish from Sonic's half-closed eyes and immediately teleported into the cell behind Infinite.
The canine's flushed expression of pleasure quickly turned into that of astonished pain as Shadow pierced his abdomnen with a chaos spear.

Driving the energy spike as deep as possible, he then pulled the jackal off of his friend and kicked him across the room, where he slammed against the wall at such a force--it dented the steel wall. 

Shadow then rushed to Sonic's side only to discover that he wasn't breathing. Holding his nose and enveloping his lips with his own, he began to administer CPR in the hopes of reviving him. The taste of blood and cum entered Shadow's mouth, but he forced himself to ignore it. All he could think about was making Sonic breathe again, of restoring life into his damaged body. 
As he pushed the chest compressions, he resounded in his mind, "No! I can't be too late!" 
Time felt like it was going by incredibly quickly, which each press showing no results. After he breathed more air into him, his determination paid off as the hedgehog began gasping for breath in a series of weak coughs. 

"Sonic. Can you hear me?" 

The blue blur cracked open his eyes slightly, but then fell limp, unable to maintain consciousness.

"I'm going to get you out of here," Shadow affirmed. He lifted Sonic's frail legs and then grabbed the chaos emerald before sliding his forearm under them. 
Semen amply dripped with blood from his anus, much to the savior's disgust. Still, in the case Sonic could still hear him, he voiced words of assurance, "You're going to be alright."

As he craddled his limp, abused body in his arms, Shadow could see the damage better up close. The blue fur stained with blood and discolored by bruises. His once powerful legs that could break the sound barrier were now emaciated and contorted, dangling gently over his wrists. The numerous punctures of canine teeth overlapped the cuts and gashes that scattered from his ears to his ankles, where layers of rope burns had left their marks. 
Bound and unconscious, Sonic was put through unspeakable hell with his body now serving as a testament to what he had endured. Shadow was holding the greatest fighter he ever knew, his rival, his friend, and yet, he hardly recognized him. He always saw that fierce spirit shine through his confident smile, which now appeared irrepairably broken.

"You're wasting your breath," laughed the jackal, who lay on the floor in a pool of his own blood. "You'll find your hero isn't what he used to be."

Shadow sneered down at him, his eyes burning red with fury.
"I'm going to rip you apart, you perverted bastard", he growled through his gritted teeth.

Infinite carefully sat up, clutching the perforated wound in his abdomen that was bleeding profusely. However, despite the pain, he was able to let out a self-amusing chuckle, "Hahaha, I'm not the perverted one. You're most likely not aware of that rodent's fantasties. How he called out your name in his sleep or how he moaned in delight at the thought that it was you penetrating him. His reactions were very...entertaining."

Shadow clenched his fist in anger, incidentally squeezing Sonic's shoulder and making the hedgehog wince in his slumber. Realizing he was hurting him, Shadow immediately released his grip and studied his face, a face frozen in a saddened expression of hopelessness that had been seared through months of torture. Sympathy, regret, anger, a combination of so many mixed emotions were beginning to take root in the heart of the Ultimate Life Form, but they were all buried under a thirst for revenge that he was temporarily quelling.

Infinite looked on with curiosity, "I wonder. Are his feelings reciprocated? How moving to be rescued by his knight in shining armor..."

In hearing the taunting words of his enemy, Shadow kicked Infinite in the face with such force that his mask shattered. As the jackal went reering back from the impact, the black hedgehog heard Sonic groan. He suddenly remembered they were in the Death Egg, enemy territory, and idling there risked capture. Besides, Sonic's need for medical attention was far greater than revenge at that moment. In an intimidating voice, he declared, "If you don't die now, when next we meet, you're going to wish you did." 
 
Infinite shifted across the floor until he leaned against the wall. Coughing up blood and laughing as he felt the internal injuries compound on one another. Slowly, he slid off his cracked mask and dropped it on the floor next to him with a clang. Looking across the room at the stained ground where he last subdued his precious captive, remembering the succulent taste of his flesh between his teeth and the sweet sounds of his screams, he uttered with a menacing grin back at his enemy, "He's mine, Shadow".  

There was no more control. No more hinderance. Shadow looped Sonic over his shoulder before sending another chaos spear flying into the smiling jackal's face. 

The deed was done. 

With the chaos emerald consuming them in its warm green glow, Shadow teleported both he and Sonic to Earth, where in the derelict building that served as the Resistance Headquarters on Earth, the green luminance caught Knuckles's attention. The control room was fortunately void of everyone else, as the Chaotix were currently deployed to the frontlines while Silver was on a supply run with Amy, leaving the echidna to monitor the war efforts solo. 
Once he noticed the source of the light was Shadow and that he was holding someone, he eagerly dashed to them with excitement.

"You found him?!" he shouted as he approached with growing zeal; however, once he got close, he stopped in his tracks, caught off-guard by what he saw.
Peering at the friend who he had known most of his life in such a beaten state sent chills through his soul. He was at a loss for words. The sound of his small rattling breaths through his congested nose made Knuckles feel on edge, but it was the sight of him that pushed him over it. Never in his wildest dreams, or nightmares, did he think he would see Sonic victimized in such a way. 

He gently rested his large hand on his friend's forehead, until he noticed the strange coloring that reflected in the dim light. "Is that...what I think it is?" he whispered, pointing out the white substance smeared in different places within his fur that eminated the noxious scent of territorial pheramones.

Shadow replied softly with disgust, "Yes...I need to clean him and tend to his wounds before anyone else sees him."

Knuckles's mind was reeling with inexplicable thoughts of what could have happened to Sonic, the likes of which turned his stomach. His hesitation to answer pressed Shadow's patience, "Knuckles!" he said sharply.

The Guardian of the Master Emerald quickly regained his senses and responded promptly, "Uh--Right! The infimary ward at the end of the hall is vacant. It should have everything you need. I'll make sure no one comes around."

Shadow nodded and carried Sonic to the medical room. As Knuckles looked on, he clutched his fists fiercely, hating that he couldn't have prevented this from happening to his friend. 

That day felt like a lifetime ago. It took weeks to get Sonic back into a healthy state, where each step of progress made two steps into regression. It was Shadow's kindness and the hero's determination that helped him want to heal, to reclaim that which was stolen from him--his freedom, his pride, his life. The blue blur was always one to rush into things, to leap before looking and taking what came in stride. He believed by throwing himself back out into the world, resuming the fight, and returning to being a hero, that all the broken pieces inside of him would fall back into place...and maybe eventually, it'd be like none of what he experienced ever happened. 

Sonic and Shadow's talk of everything that occured made both hedgehogs realize just how wrong they were. 

"I only remember that day in my nightmares," he admitted as the two sat on the edge of the bed side-by-side. "But then again....a lot of those memories do the same."

"I'm sorry," Shadow stated without looking directly at him, "I overlooked the signs. Had I known you were still struggling, I would have done something sooner." 

Sonic held himself as he looked to his black and red counterpart. He could see the guilt flowing over the side of his face. Seeing Shadow beat himself up made the blue blur feel guilty as well. He had to be honest with him...and himself. 
"There was nothing you could do, Shads," he began, "I was too stubborn to see the signs myself until I couldn't control them anymore. I probably wouldn't have accepted your help even if you tried."

"Why"

"Cause I vowed I was going to get better--that I was going to put everything that happened to behind me and not let my demons win. Acknowledging I still had a problem was the same as admitting defeat and turning to anyone about it was the same as blaming them for their failures."

"You don't give your friends much credit. You know they'd do anything for you...and so would I," he said as he placed his hand on Sonic's. 

The blue hedgehog blushed slightly. Shadow's caring side always made him more attractive, and the warmth of sincerity in his touch always made his heart both flutter and calm at the same time. However, his mind was still on the issue he was dealing with that wouldn't leave him be and this whole ordeal made him realize that he couldn't run away anymore. Taking his partner's words into account, he made an obscure request. 

"You....you said you would do anything for me, right?" he inquired in a tentative whisper, "Can you take me back to the Death Egg?"