The group had barely taken a step before the dilapidated window shattered with a loud CRASH! A familiar figure hurtled through it in a blur of green and blue, letting out a pained cry before landing hard on the wooden floor. The others were frozen with shock for only a few seconds, then Raph was the first to leap forward.

"Leo!"

He heard the others' running feet behind him, but all his focus was on his blue banded brother. Dropping to his knees, he scanned Leo's battered form with frantic eyes. The signs of a fight were clear in the cuts and bruises, but his eyes quickly moved to the slider's left side. His hand weakly clutched a spot near his ribs, and Raph's alarm only grew when he saw red. Carefully, he lifted Leo's hand and his stomach dropped.

The gash cut clean through the shell just under the rib cage, bleeding heavily. From the look of it, Leo had dodged just in time to keep it from being lethal. Raph slipped a hand under Leo's head, pressing the other to his side and struggling to keep the panic out of his voice.

"Leo? Little brother, can ya hear me?" His brother's eyelids twitched, and a faint groan escaped his clenched teeth as they fluttered open to reveal pain-glazed eyes.

"Leo, what happened?" Raph persisted. "Who did this t' you?" The slider winced, clearly struggling to focus, but before he could say anything, Donnie was kneeling on his other side.

"Move your hand!" he ordered Raph without looking at him. "Let me see it!"

The eldest turtle obeyed, his heart twisting at the blood staining his hand. Donnie's brow furrowed even deeper as he examined the wound, his mouth tight.

"It's deep… I'm not sure what could've caused it, but…"

Before he could finish, a sharp exhale drew everyone's attention to Casey. He was frozen in place, eyes wide and face pale.

"Casey, what's wrong?" Mikey asked, his own eyes full of fear. For a moment the teen didn't seem to hear, then he swallowed hard.

"I… I've seen this before." The raw fear in his voice sent a chill down everyone's spines.

"Where?" Donnie demanded. Casey tore his eyes away from Leo, and Raph saw them move to him. When he realized what the teen was looking at, he suddenly felt as if his veins were filling with ice water. Reaching up a trembling hand, he ran it over the damaged portion of his shell. Phantom pain throbbed through it at the sensation.

"No…" he muttered. "No, that's… that's impossible…"

He stood and was about to move to the broken window, but Leo's hoarse, weak voice stopped him cold.

"R-Raph… wait…"

The snapper turned to see Leo lifting a trembling hand, and immediately moved to kneel back down. His brother took hold of his arm, prompting him to lower his head.

"H-he's back…" Leo rasped. "The… Shredder."

Raph felt as if someone had punched him in the stomach. Though a small part of him was relieved Leo hadn't said 'the Krang', the rest was filling with a cold dread. How was that possible? They'd defeated Shredder… they all saw it with their own eyes! But before he could say anything, Leo cringed and let out another groan as his eyes closed and his hand slipped from Raph's arm.

"Leo!" Mikey cried, his voice shrill with panic.

"Shh!" Donnie hissed. "Whoever it is, they're out there now!"

He'd barely completed the sentence than sounds began coming from outside: faint moans and growls. Raph felt a chill run down his spine… he knew those sounds. Standing again, he moved to the broken window. Back pressed to the wall, he looked out. He was pretty sure what he would see, but still cursed.

"Raph?"

The eldest turtle looked at the others.

"Foot. Looks like they're all around th' building."