After receiving a message from a spiritual messenger, the Turtles go on a quest for spiritual refinement in preparation for what's ahead.
- Astral Projection: Splinter clarifies he is not dead, but his spirit has left his body.
- Attention Deficit... Ooh, Shiny!: This flaw of Mikey's is faced head on in this episode. As Master Spliner puts it, he must be calm and still "like the Forest."
- The Bus Came Back: Splinter and the Foot Clan make their first appearances since the second season finale.
- Clap Your Hands If You Believe: In the episode's climax, Leonardo realizes that his leg had fully healed and that his pain was entirely psychosomatic: his fear of failing again is weighing him down, his leg an excuse not to try. Once he realizes this, the pain not only goes away, but he immediately adapts to the Spirit Plane's liminal nature and defeats his opponent.
- Disney Villain Death: In order to defeat Tiger Claw, Donnie sweeps his leg and throws him off the mountain.
- Don't Think, Feel: Splinter advises this to Donnie. He says Donnie relies not enough on his body and he must stand his ground to be "strong like the Mountain."
- Elemental Motifs: Each turtle is assigned a natural element by Splinter for purposes of their individual vision quest themes. Leo is Air, Raph is Fire, Don is Mountain, and Mike is Forest. Each one correlates to how they need to improve and perfect themselves.
- Evil Counterpart: The Turtles face off with their evil counterparts during their quest.
- Leo Vs. Shredder: The leaders of their respective clans.
- Mikey Vs. Rahzar: The Butt-Monkey's of their teams who have a minor rivalry.
- Donnie Vs. Tiger Claw: Mostly Pair the Spares. Though Tiger Claw is not the Evil Genius of the Foot, he is still highly intelligent and is The Dragon. Donnie has been seen in a Number Two position to Leo before, even if it's usually Raph's role. Furthermore, both are associated with technology the most in the team.
- Raph Vs. Fishface: The Boisterous Bruiser's of the team, a fact acknowledged way back in the first season.
- Evil Laugh: Tiger Claw enjoys quite a few of these when fighting Donnie.
- Eye Scream: Leo defeats Shredder by shooting an arrow into his eye.
- Leaning on the Fourth Wall: When Rahzar first appears to Mikey.Rahzar: Been a long time...
- Let's Get Dangerous!: After seven episodes of almost pure filler and bizarre mutants and foes, this episode puts the series back on track to return to New York.
- The Marvelous Deer: The spirit deer is the herald that kicks off this whole adventure. It also has a humanoid form.
- Mythology Gag: Splinter's spirit appearing to the Turtles around a campfire in the woods has appeared a few times in the mythos and is yet another direct link between this arc and the second act of the original live action movie.
- Shredder kicking in Leo's leg is reminiscent of when he did the same to Mikey in the third season finale of the 2003 cartoon.
- Out of Focus: April and Casey are left out of the spirit quest, as the former has not completed her training and the latter has not trained in ninjutsu at all.
- Shout-Out:
- Raph sarcastically notes the lack of a pirate ship in the underground lake. Doubles as an Actor Allusion for his VA, Sean Astin.
- The deer that acts as a spirit guide sometimes turns humanoid.
- The fights the Turtles have with the Foot Clan have vibes of Luke encountering Darth Vader in the Dagobah swamp.
- The poses the four Turtles do when they show off their new weapons and armor, against a red background with Japanese characters, are highly reminiscent of the opening of fellow Nick series Avatar: The Last Airbender.
- Finally, the four kanji brought together spell out Fuurinkazan, from an actual Japanese philosophy, but is now mostly known for being the words on Ryu's belt.
- The Voiceless: The spirit deer who guides the Turtles, Leo in particular, on their spirit quests.
- Wham Episode: Leo has fully recovered physically and emotionally, the Turtles have attained spiritual refinement, and decide the time has come to return to New York to face the Foot and the Kraang.
