|Season 4, Episode 21|
|Airdate||November 13, 2016|
|Prev. and Next|
The Super Shredder
The Power Inside Her
Darkest Plight is the 21st episode of Season 4 and the 99th episode overall.
The Turtle team hunts for Splinter, but soon realizes they are being hunted as well.
Continuing from the events of The Super Shredder Shredder and Splinter plummet into the abyss, Shredder manages to land on a metal I-beam while Splinter bangs his head on several more before finally reaching the bottom of the abyss.
Back with the Turtles, Karai, and April, they manage to escape Bebop, Rocksteady, and the Elite Foot-bots and return to their lair. Casey arrives and learns of Splinter's fate, and fully supports the rescue effort the Turtles make to go find Splinter. While Mikey goes looking for Splinter, the rest of the team will protect him from Shredder and his goons.
As for Shredder, as he climbs back to safety, Tiger Claw helps him up, then is horrified upon seeing Shredder's left hand in its current state, and warns Shredder that any more mutagen could be dangerous. However, knowing that Splinter is still alive, Shredder wants Zeck and Steranko to remain in the under-city and look for him.
As for Splinter, as he comes to and places his leg in a makeshift splint, he discovers to his disbelief that Victor Falco is still alive. As Falco taunts him and tries to convince him to fall back under his control, when Splinter refuses, Falco covers himself with rats to assume a more monsterous, rat-like form to devour Splinter.
As for the Turtles, Donnie and Mikey descend with their grappling gear to find Splinter, leaving Raph and Casey to deal with Bebop and Rocksteady. Leo, April, and Karai remain behind as April senses Super Shredder and Tiger Claw's approach, and flee for the surface. Under orders from Super Shredder, Tiger Claw goes after April and Karai to bring Karai back alive to Super Shredder, but Karai assumes her mutant form to knock Tiger Claw onto some power lines, electrocuting him and knocking him out. Leo is separated from the girls to face Super Shredder alone, who knocks Leo out into the street, causing a panic amongst the innocent civilians, before attempting to crush him between his hands. Luckily, April and Karai arrive to help, with April using her psychic powers to try and beat Super Shredder herself. During the fight, after Super Shredder is smashed into a building by a fuel tanker truck, he tosses the truck towards Karai, but April is able to catch it with her psychic powers. After some struggling, April's Aeon crystal soon gives her the strength to succeed, causing her eyes to glow a bright blue and smile almost malevolently, before she tosses it aside. However, it leaves her too fatigued to help Leo as Super Shredder prepares to kill him. However, Karai pleads with Super Shredder to not do this, trying to convince him to do something good with his life instead of be consumed by his vengeance. Touched by this, Super Shredder tries to apologize to Karai, but it was all a ruse as Karai punches him in his mutated heart, leaving him weakened and in need of mutagen once more. Tiger Claw quickly arrives to retrieve Super Shredder and prevent Karai from pursuing, while Karai gives up the chase to help April get Leo back to the lair for medical attention.
Meanwhile, Casey and Raph are able to defeat Bebop and Rocksteady, while Splinter is able to overpower the rat monster when he nearly succumbs to his feral instincts, until a vision of the Turtles and Tang Shen allows his humanity to retake control, leading him to soon discover that it was all a hallucination brought on by his fever, as he soon discovers Falco's skeletal remains, and is then rescued by Donnie and Mikey.
Back at his hideout, Super Shredder demands a larger dose of mutagen to stabilize his condition, but Tiger Claw tries to stop him, saying that any more could destroy him, but Super Shredder overpowers Tiger Claw, pins Stockman to the control panel, and forces him to administer another dose. Tiger Claw can only watch in shock and fear as Super Shredder lets out an enraged scream as the mutagen strengthens him once more...
- The Rat King's skeleton is shown, confirming that he is deceased.
"We have salmonella"-Mikey to Bebop, and Rocksteady.