The Turtles staggered back into the lair after a long and exhausting mission. Their latest encounter with the Foot Clan had left them battered and bruised, but victorious.

“That’s it,” Raph groaned, dropping onto the couch. “Next time, someone else can take on five foot-bots at once.”

Mikey flopped onto the floor, nunchaku still in hand. “Ugh, I’m too tired to even think about pizza. That’s how bad it is.”

“Stop complaining,” Donnie said, wiping oil from his bo staff. “We made it back in one piece, didn’t we?”

Leonardo scanned the lair, frowning. “Where’s Master Splinter? He usually greets us after missions.”

As if on cue, Splinter emerged from the shadows, his expression unreadable. “My sons, come here. There is something I must discuss with you.”

The Turtles exchanged wary glances before gathering around him.

“What’s going on, Sensei?” Leonardo asked, sensing the seriousness in his father’s tone.

Splinter hesitated for a moment, his gaze heavy with emotion “When you guys were out, there was a break in at the lab that is located across the city. It was serious. I went out, planning to try and stop it because you boys were already out.” He paused

“And I found someone I lost years ago…” He paused again before leading the boys the room you were standing confused in.

“This, is your long lost sister…” Splinter said calmly.