With the dark armor nearly complete, the Turtles decide to get serious and embrace their ninja heritage.
Tropes:
- Bait-and-Switch: When April asks where the Foot Lieutenant where he's moving a piece of the dark armor, he gives her a look and it seems like she's given herself away, only for him to gladly explain.
- Bring It: At one point, Raph and the Foot Recruit beckon for the other to approach. Neither does, so they just beckon faster and faster.
- Chekhov's Gun: The tea pot that Splinter is using is actually the Faceplate for the Shredder's helmet.
- Comically Missing the Point: Some Foot ninja see a wing-suited Splinter fighting with a pigeon and mistake it for two birds in love. Not much later, Splinter calls April a ninja supreme and she mistakes that for a pizza order.
- Did You Get a New Haircut?: The Foot Brute asks this upon seeing the turtles' new uniforms.
- Disappointed in You: When Splinter finds out that his sons missed out on the mission due to getting caught up in a prank war, he somberly says this trope and walks away.
- Downer Ending: All four Turtles, plus April, get captured.
- Gale-Force Sound: April presses Donnie's panic button, which makes an announcement so loud it blows off her disguise.
- I Meant to Do That: After accidentally taking out the Foot guards, Splinter claims that went just like he planned.
- Mass "Oh, Crap!": The turtles have one when Baron Draxum appears and grabs April, followed swiftly by them.
- Mythology Gag: All the turtles swap their original colors for red, and in doing so, look like the Mirage turtles.
- New Powers as the Plot Demands: The ninja mind meld. Raph even states "it's a thing we do now."
- O.O.C. Is Serious Business: Because of the stakes, April is quick to notice how out of character the Turtles are while in the train. They aren't as jokey, they don't bicker, Raphael pays attention to small details, and Donnie doesn't rely heavily on his tech skills.
- Parallel Conflict Sequence: We are treated to the delightful sight of the turtles taking on different opponents in different train cars. Mikey and Donnie face the foot Lieutenant and Recruit, while Leo and Raph fight a pair of yoke guards.
- Pose of Supplication: The turtles get on their hands and knees while apologizing to Splinter for their latest screw-up.
- Practical Joke: The turtles appear to be in some sort of prank war at the start of the episode.
- Sand In My Eyes: Splinter is so proud of the boys' progress that he sheds a few Tears of Joy. When the Donnie points this out, he claims that he smells onions in the air.
- Something We Forgot: Splinter apparently forgot about April while training the turtles. He only remembers when Donnie brings up her panic button, causing him to drag them on a rescue mission.
- So Proud of You: While he doesn't say it out loud, Splinter is obviously proud of how far his sons have come in their training.
- Spirit Advisor: Splinter summons the ghosts of his ancestors for advice on what to do about the Shredder's impending revival.
- Tempting Fate: When the Foot Brute notices April, he notes how her friends aren't around. Cue the turtles barging in. He lampshades this.
- Training Montage: The turtles get their butts kicked by Splinter multiple times and give up most of their possessions to avoid distractions. It pays off when they finally defeat their father in a sparring match, resulting in him giving them new uniforms.
