At that very moment, as his brothers were caught in a firefight with a squad of Kraang-droids, Donnie was trying to call April back on his T-Phone. He was in a total state of worry, oblivious to the blaster fire that whizzed all around him. Leo attempted to reason with him in a firm but calm tone. “Donnie, focus! April can take care of herself.”

“Against Karai?” Donnie asked in a frenzy. April barely knew how to throw a punch, and Karai had nearly taken out a Kraang spaceship on her own! “Are you kidding? I’ve gotta help her!”

“You’re not gonna be much help if you get blasted in the head!” Leo yelled.

“Whoa!” Donnie shouted, ducking an energy bolt that nearly scorched his scalp. “Good point!”

Time to get my shell in the game! Donnie thought, charging into battle with his brothers.

Leo broke through the Kraang first, his katanas slicing and dicing through two droids at once. Donnie was right behind him, unleashing his bo staff at the last second for a surprise attack. The backup bots never knew what hit them. And just as two remaining Kraang-droids were about to open fire, their titanium bodies hit the floor, thanks to Mikey’s sweet sweeper kick.

“That’s a twofer!” Mikey bragged, gratefully bowing to an imaginary crowd like a rock star finishing a sold-out performance. “Thank you. And thank you. And thank you.”

Two Kraang-droids suddenly appeared behind Mikey, readying their blasters, and Raph rushed into action. He vaulted himself into the air, surprising the bots with a nose dive–style sai strike. He skewered them to the floor before they could squeeze a trigger. They were nothing but scrap metal now.

“How many times have I told you no celebrating until the fight is over?!” Raph scolded Mikey.

“How many times have I told you I assumed it was over?” Mikey retorted, jabbing Raph with his finger. Raph grabbed Mikey’s hand and squeezed. Hard.

Mikey screamed.

Donnie couldn’t believe this! Were they really having an argument now? He got between them before it got any worse. “Children! Children! We have got to go.”

“Um, have you forgotten about a little something called completing the mission?” Leo said, reminding them all why they were standing in the middle of an underwater base in the first place.

“But April’s in danger!” Donnie insisted.

“If we leave now, the Kraang will poison everyone in New York,” Raph reminded him. “Which, last time, I checked, includes April!”

“Think, Donnie! How do we take this place out?” Leo asked.

Donnie scanned the control room around them, trying to concentrate on finding a solution. How were they going to destroy this facility? He needed a hint, a sign of some kind.

“The chemical is highly explosive,” Donnie said.

“How do you know that?” Mikey asked.

“Partly because it has hydrocarbon on its outer ring,” he explained. “And partly because of that sign,” he added, pointing at a picture on the wall.

They all looked up. There was a warning diagram showing a Kraang exploding out of a droid body.

Donnie swiped a blaster from one of the bots lying motionless on the floor. “Raph, you think you can get this blaster open for me?”

Raph spun one sai with a wicked smile. “With pleasure.”

“But before you do, be careful you don’t—”

Before Donnie could finish, Raph stabbed the weapon, peeling off half its metal casing with one swipe. Donnie winced and shut his eyes. He nervously peeked a moment later.

“Oh, good, we’re still alive,” he said with a sigh. He fiddled with the blaster’s wiring. “Now I’ll short out the power supply and leave it by the chemical tanks. It’ll overheat and the whole place will go boom.”

Once the blaster was ready to detonate, Donnie and the other Turtles got into position. Leo and Raph ran across the room, directly under the chemical tanks, which were mounted to the ceiling. If Donnie was going to plant the explosive up there, he was going to need a boost.

So, like gymnasts prepping for a routine, Leo and Raph locked arms, forming a launching pad. Donnie sprinted toward them, vaulted off their arms, and propelled himself through the air. He arced over the room, getting some serious hang time, and planted the blaster perfectly.

“There,” Donnie said as he dropped to the ground. “In about ninety seconds, this whole place is gonna blow.”

Satisfied that their mission was nearly complete, Leo gave the go-ahead. “All right! Let’s move!”

Donnie redialed April on his T-Phone. He heard her panting when she picked up. “April, what’s your status?”

“Could … be … better!” he heard April yell.

“Okay, we’re on our way,” he assured her. “We’ll be there soon.”

The Turtles ran back to the only exit in the entire facility: the reentry pool. All they had to do was jump in, swim back to the Sub, and they’d be home free.

But something was wrong. The water was rumbling. Something big was coming through the watery portal. A long, snakelike neck emerged from the pool. Towering over the Turtles was a scaly amphibian beast with rows of sharp fangs.

It was the sea monster!

“Uh, actually, there might be a slight delay,” Donnie said into the T-Phone.

They were trapped!