Donnie

Blood had smeared onto the wall from Leo's hand as he propped himself up in his cell. Tiger Claw had captured him and knocked him out cold so he couldn't even guess where in the state of New York he was, or if he even was in New York at all.
Taking in his surroundings, he immediately took notice on how he couldn't extend himself to his full height. The back of his shell pressed uncomfortably into the rounded ceiling. The cell itself was not large. Enough for him to sit cross-legged, but not more than that. He'd have to sleep inside his shell for any kind of comfort.

"Slept well, turtle?"

Leo's eyes were immediately drawn to the stronger source of light coming from what he could guess to be twenty feet away. The voice belonged to Tiger Claw, but his new attention was drawn to what was behind him. What he could use to his advantage to escape and if there was an indication as to where he was. Tiger Claw approached him and held up a thing fabric of cloth silhouetted against the light. It took Leo a moment to realize that it was his mask, and his blood immediately began to run red hot under his skin.
"Oh? Not more mad than that? Take a closer look, turtle."
Tiger Claw held it higher, forcing Leo to squint his eyes a bit more at the mask. It didn't really come into focus until blue turned into purple. It was Donnie's band.
"You..."
He growled out, teeth gnashed together in absolute fury. "What'd you do to my brother?" A grin flashed across Tiger Claw's face. A deep, absolute hatred began brewing in Leo's gut as his hands white-knuckle gripped the cell bars.
"ANSWER ME."

Tiger Claw didn't have to. Hidden against the tiger's massive physique was Donatello's staff; which he leaned against the wall and tied his mask onto.

"You didn't..."

"I did. And not before he ratted out where the others are."

"HE WOULDN'T."

Absolute in his defiance, he rattled the bars with all his might in desperate attempt to loosen them. "LET ME OUT OF HERE."
"Hmph. Don't ask me that as if I'd just hand you the keys, turtle. There aren't any. You see that wall behind you? Well, that's newly made. You've been unconscious for so long, we had time to build an entire wall around you."

White-washed with fear and anxiety, Leo turned around and felt the rough curves of the wall behind him. It was as if someone had hastily poured cement over cinder blocks and let it set haphazardly. They probably did, he deducted. Looking in front of him, he also quickly realized that the bars had no door. They were just that-bars bolted to the ceiling and then floor. Leo had never been one to be claustrophobic, but the idea of being completely and utterly unable to get out terrified him. There literally was no exit, and the bars would never move. The very air suddenly began to suffocate him.

There was no way out.

"Where's my brother."
His voice nearly betrayed him as he made his demand. Tiger Claw shrugged and grinned. "I could keep the body here if you'd like. But I thought I'd at least do you the courtesy to cremate him. Unless you don't want that..."
"You're lying."
"Am I?" Tiger Claw 'tsk'd' him and turned around, motioning towards someone outside. In all his glory strutted in Xever carrying a mutilated Donnie. His outer shell looked to have been clipped away. His head had been cracked open and skin peeled away to show off parts of his skull that glistened with blood in the light.
Blood.

The putrid stench wafted all the way over to Leo's enclave and caused him to keel over and vomit without warning. "No...no, no, no!" His eyes widened as he looked over at the doorway once more.
"Was great with this one," Xever mused, tossing Donnie onto the wet floor with a heavy thud. Light cascaded onto his face, revealing larger gaps in his mouth that had initially been there with a heavily swollen lower jaw. Teeth had to be missing. "All his secrets spilled within two minutes. That was no fun at all. The younger one should prove much more enterta-"

"IF YOU TOUCH MIKEY, I'LL END YOU."

Leo bellowed, his throat on fire from the vomit. This wasn't true. This couldn't be happening...Donnie was...Donnie couldn't be.
"Finish off the other one. We'll be back yet, turtle." Leo's eyes fell upon the limp figure of his brother sprawled out on the ground before him. He wanted to reach out and cradle his younger brother in his arms; to try and rouse him from his eternal slumber and undo the damage wrought onto him. To tell him that it was all his fault. That they shouldn't have gone into Shredder's lair without telling Splinter.

"We'll be back with the other one, don't worry." Xever cackled as he walked out, wiping imaginary tears from his eyes. Tiger Claw looked down at Donnie and pushed his limp arm out of the doorway with his foot before closing the door behind him, darkening the room once more save for a sliver of light that shone from a crack beneath the door. There were no words exchanged between hero and villain. Just a somber silence that welled up so heavily inside Leo's chest that he tried to call out to his brother fervently.
"Donnie! Donnie, c'mon, bro, stop playing around! We need you, man!" Of course, he didn't move. The small glimmer of light had illuminated only just a portion of Donnie's face.

"DON!"

Nothing. Leo even tried holding his breath to see if he could hear Donnie breathing at all from where he lay. It was fruitless. He was...he was gone.
And now it was Mikey's turn and he was completely powerless to do anything about it.