Notes:

This story takes place in the excellent IDW comics continuity of TMNT, and if you haven't read them, you should do so right now. They are awesome. WARNING: This takes place after the notorious Issue 44, and will contain a lot of spoilers for what happens in it. So if you don't want to be spoiled, go read the series and come back after you've reached that point.

This is an AU version of the Vengeance arc (issues 45 to 50) where Donatello's mind was never successfully placed in the Metalhead body, and thus his brothers are forced to fight on without him. Some things about it will be the same as in the comic series, others will be very different.

Chapter 1: Blood

His hands were still stained with blood. He hadn't noticed it when he and his brothers had moved Donatello to the cooling unit, but now it was all he could see — dark stains marring his green skin.

Blood. Blood. Donnie's blood. It seemed to be everywhere. The lab reeked of blood; it had pooled on the floor, had fallen in a stream of tiny scarlet droplets across the concrete as they carried him, as gently as they could. He could smell it in the air, lingering long after Donnie had been removed from the room.

It had been over an hour since Fugitoid and Harold had vanished into that room. Perhaps two hours. Leonardo had no idea what they were doing to Donnie, or if all of it was in vain. But he clung to the hope that the alien robot would know something that could save his brother. Anything.

Leonardo had never felt so useless in his life. Even when victory required something more technical — more something in Donnie's field of expertise — Leonardo had always been able to find something to do. Now, there was nothing he could do but wait. Wait and pray. Wait and dread whatever might come next.

He glanced up at the massive steel door to the cooling unit. Mikey had been crouched beside it ever since Fugitoid had returned, whispering prayers into his clenched fists. Raph sat opposite it, as if staring down an enemy that he was itching to fight, his reddened eyes still gleaming with rage. Alopex was sitting near him, her face still full of sadness, while Angel was anxiously pacing the floor.

Leonardo didn't feel either desperation or rage. Mostly he felt numbness seeping through his spirit, keeping him from responding at all. If Donnie were awake, he would probably say that Leo was in shock from what had happened… but he wasn't awake.

All Leo could do was roll back time to when they had first arrived at the lab, the burst of exultation that had filled him as he prepared to tell Donnie of their success. The Foot Clan was decimated. Krang was gone. And though Burnow Island had been terraformed, the rest of the planet was safe from the Technodrome. They had done it. They had won.

But all that joy had withered away as they saw Donnie, his head resting in Splinter's lap, a pool of deep crimson blood under his broken, lifeless body. His shell had been smashed open like a rotten pumpkin, and he had been left there to die, to bleed out like a slaughtered animal. Alone. In pain. Frightened of what had happened to him…

Leo swallowed hard, and his bloodstained hands clenched into fists. Harold Lillja had told them what had happened before Fugitoid returned. The normally acid-tongued scientist had stammered out what he had seen from a distance, from behind the safety of a computer screen. Leo knew it was irrational to be angry at the man for being safe while his brother was beaten to death, but a flicker of rage was stirring up inside him at the thought.

Shredder had left Bebop and Rocksteady there to guard Donatello, and to kill him if he betrayed the Foot. Maybe he would have ordered Donnie's death regardless of what had happened. Leonardo hadn't known of this — no one had, except Harold and Donnie.

And those monsters had done their best. Those beasts — the towering brutes that had barely been stopped by a building falling on them — they had attacked Donnie and done their best to kill him. Leo had since taken a look at the security footage from the lab, and he was sickened by what he saw. His brother had tried to flee, tried to fight. But they had smashed him with computer components, punched him with their enormous fists and immense strength, crashed him into concrete pillars, and finally Rocksteady had smashed a sledgehammer into Donnie's shell, cracking it wide open.

And now all they could do was wait. Wait and wonder. Splinter had been gone for the past few hours, meditating in a dark corner of the laboratory. Leonardo suspected that he knew what his father was doing — trying to call Donatello's soul back before it was lost to them forever. Healing his body was useless without his spirit choosing to live.

Suddenly the steel door swung wide open. Fugitoid was standing there.

For a moment, he stared intently at Leonardo, as if trying to unravel a puzzle. Then he pointed a metal finger.

"Leonardo, I need your help. Quickly!"

Leonardo didn't hesitate.

"Hey, what the hell is going on-" Raph shouted.

His voice was cut off by the clang of the door shutting behind Leo.

He took a deep breath of the cold air, steeling himself for whatever he was about to see. Donnie was lying there at the other end of the unit, limp and lifeless on a rolling hospital bed, with a sallow-faced Harold lurking behind him. Oddly enough, the Metalhead robot was crouched down beside the bed.

"What is it? What happened?" Leonardo said.

"I attempted to transfer Donatello's consciousness into the Metalhead robot. Come this way." The robot pulled Leo gently but firmly to his brother's side.

"You… you did what?"

"It didn't work," Fugitoid said despairingly. "Donatello's life — his soul, for want of a better word — is too far removed for the process to work. He's — unstable."

"How can I help?" Leonardo said.

"My sensors indicate that you have the same blood type as Donatello. He's suffered massive blood loss as well as internal damage, and reviving him will be next to impossible without a transfusion."

The robot wheeled a large, complicated-looking machine covered in a thin whitish metal, with many long hoses and needles sprouting from it like a squid's tentacles. Leonardo wasn't sure, but he suspected that it wasn't a machine from Earth - perhaps one of those machines the Fugitoid had brought from Burnow Island.

"Take as much as he needs," Leo said grimly, holding out his arm. He almost said Take it all if he needs it, but knew that it wouldn't help.

Fugitoid needed no further urging. He pressed his metal finger against Leonardo's arm until a vein rose under his green skin, and slid one of the machine's many needles into the flesh of his upper arm. A thin stream of dark red ran down the tubing to the machine itself, which whirred faintly.

Leonardo let out a breath he hadn't been aware he was holding, and glanced up at Donatello. Fugitoid was bent over his brother, arranging other tubes and sensors that littered Donnie's arms and torso.

"The transfusion has begun," he said at last, stepping out of the way. Another tube from the machine had been inserted into Donatello's arm, and the blood — Leonardo's blood — was streaming into his body.

"Damned useless," Harold muttered, shaking his head. "I feel damned useless."

Leonardo kept his eyes intently fixed on Donatello's face as his blood flowed into his brother. Some sign of consciousness, some hint that he wasn't as lifeless as he looked. But the minutes ticked by in silence, and Donatello remained pale and limp, his face haunted by a ghostly echo of the pain he must have felt.

Suddenly, Fugitoid shut down the machine, and deftly slid the needle from Leonardo's arm.

"What? Why are you stopping?" Leonardo said, confused.

"We've already transfused more of your blood than it was safe to take," the robot said, removing the needle from Donatello's limp arm.

"You can't stop because of —"

"Leonardo," Fugitoid said, placing a hand on his shoulder. "Please trust my judgement. If Donatello's internal injuries are not as bad as I first feared — if he doesn't currently have internal bleeding — then you may have greatly increased his chances of survival."

Leonardo took a long shuddering breath, and moved closer to Donnie's bed. His brother looked… looked wrong like that. Not just sick and still — it was far worse than that. Bruises mottled his olive skin where Rocksteady and Bebop had struck him, and thin streams of blood had dried on his chest and throat. His broken shell didn't seem to be bleeding anymore, but somehow that made the silence, the stillness even worse.

Donatello didn't look injured. He looked dead.