A day of training in the park goes south when the Turtles see an alien spaceship explode overhead. The occupant, a strange purple extraterrestrial, is barely alive after the impact, but manages to warn the heroes about the "Eye of Sarnoth," a crystal formed from three fragments of his craft. When combined, the Eye grants "power undreamed of"—something that Shredder, who is spying on the Turtles, overhears. Before dying, the alien begs the group to find the fragments, giving them a rare "Crystal Converger" that can sense their energy signature. He then disintegrates, and the Turtles begin their search for the first piece of the Eye.
Shredder follows the Turtles with aid from Baxter Stockman (and no help from Krang, who refuses to send any Foot Soldiers to Earth until Shredder defeats the heroes in a half-shell). The Turtles discover the first piece of the Eye of Sarnoth in a garbage barge, but Shredder swipes it after defeating them in combat. He then discovers that the crystal can cause objects to shrink—a power demonstrated when the Turtles themselves are miniaturized. Though they escape, Shredder and Baxter begin a citywide attack by shrinking major landmarks, including the Empire State Building.
After his students return to the sewers, Splinter contacts April to gain surface aid in searching for Shredder and the Eye fragment. While they explore, Leonardo, Donatello, Michelangelo, and Raphael are swept up in a storm surge and flushed out to sea, where Baxter catches them with help from a tracking device he built. The miniaturized and trapped Turtles are almost killed...until Splinter and April drive through the door of Shredder's hideout. While Splinter squares off against Shredder, April manages to recover the Eye of Sarnoth's piece and reverse its power, restoring the Turtles to their normal size. Unfortunately, Shredder is able to steal the fragment back and escapes with Baxter. Splinter assures the turtles that failure is itself a teacher, and the Turtles vow to keep searching for their archenemy and the remaining crystal pieces.
Tropes
- A Day in the Limelight: Splinter shows off his own impressive combat skills during a one-on-one duel with Shredder. This was among the first times the Turtles' teacher got a chance to prove just why he is considered a ninja master.
- The Bad Guy Wins: Shredder and Baxter escape with the first fragment of the Eye of Sarnoth for themselves. This leads to An Aesop about failure being a part of life.
- Big Damn Heroes: April and Splinter get to pull this off by crashing the Turtle Van through the boarded-up doors of Shredder's hideout just before he is about to kill them with a crowbar.
- Character Death: The alien pilot disintegrates upon his death. Notably, this is only time death is shown in the series onscreen.
- Contrived Coincidence: The Shredder happens to be hiding behind the bushes when the Turtles learn about the fragments.
- There's also the fact that the alien spacecraft explosion that kicks off the plot just so happens to occur right above where the Turtles are training.
- Curb-Stomp Battle: Shredder, of all people, delivers one to the Turtles when they square off against him at the docks. He's able to defeat and capture each of them without breaking a sweat. Particularly notable moments include him chopping a wooden support beam in half to knock out Raphael and effortlessly disarming Leonardo with a quick feint and kick.
- Gotta Catch 'Em All: An extremely limited example of this trope shows up with the Eye of Sarnoth's three fragments. This episode and the few that follow it are all about the Turtles and Shredder racing to collect the pieces.
- I'm Dying, Please Take My MacGuffin: The alien pilot summons the strength to give the Turtles a Crystal Converger that can track the three Eye of Sarnoth fragments before he disintegrates.
- Incredible Shrinking Man: The Turtles, obviously.
- I Need to Go Iron My Dog: April receives an urgent summons from Splinter in the middle of a news meeting and heads out claiming that she's following a "hot story." Considering that this episode was made before cell phones were widely used, her suddenly hearing about a scoop in the middle of the day is highly unlikely.
- Baxter, who's eating ice cream at the time, also falls into this when Shredder demands assistance:Shredder: Baxter! Connect me with Krang in Dimension X immediately!Baxter: BUT MY CONE IS MELTING IN THE SUN.
- Baxter, who's eating ice cream at the time, also falls into this when Shredder demands assistance:
- Ironic Echo: Burne has a meeting where he tells everyone that in the news business they have "to make split-second decisions". But then the meeting is interrupted by April's Turtle-Com.April: I gotta go, Burne. It's a hot story.
Burne: Go where? We're in the middle of a meeting.
April: You said it yourself, "we've got to make split-second decisions". Ciao.
[April leaves the room]
Burne: But that was only a speech! - Laughing at Your Own Jokes: Shredder drops a pun after taking down the Turtles, then chuckles to himself and remarks "Oh, I made a funny!"
- MacGuffin Delivery Service: Shredder, lacking the ability to track the Eye of Sarnoth's pieces, simply lets the Turtles do so, then swoops in to snatch the first fragment after they find it.
- Mineral MacGuffin: The three fragments of the Eye of Sarnoth are small crystals that can be fused together.
- Monumental Damage: The "crown jewel" of Shredder's shrunken city collection is the Empire State Building, one of New York City's most famous landmarks.
- Mouse World: The Turtles encounter this when they're miniaturized by the Eye of Sarnoth's piece—a sewer trickle becomes a massive tidal wave, and a tiny fish is suddenly an apex predator. They also discover the perks when a single slice of pizza is enough to feed them all.
- My Significance Sense Is Tingling: Splinter develops a never-before-seen ability to inherently know where the Turtles are, explaining that "the bond between sensei and student is very strong." It works well enough to let him give April directions to Shredder's latest hideout.
- No Body Left Behind: After the alien gives the turtles the crystal and exposits to them about the Eye of Sarnoth, he vanishes in a green light.
- No Endor Holocaust: Despite Shredder shrinking roughly thirty buildings in Midtown Manhattan, no one seems to be affected during the attack. When the Empire State Building starts shrinking, people are shown running out the doors, so presumably everyone evacuated before the edifices became too small.
- Not So Above It All: Splinter, who usually plays the role of The Stoic as the Turtles' teacher, arranges for specially-made miniature pizzas to be delivered at the episode's end to gently Troll them.
- Paper-Thin Disguise: At the episode's beginning, "Shredder" attacks the group—but it's clearly Michelangelo in a purple blanket and poorly-made mask, with his green arms still clearly visible. Despite this, his brothers are successfully fooled.
- Story Arc: The beginning of the Eye of Sarnoth arc.
- Unusually Uninteresting Sight: When the Turtles go searching for the first piece of the Eye, they arrive at the city docks. In broad daylight. With other people around. No one comments on the six-foot mutants who've just emerged from a giant van, or the guy in the the metal mask and purple cape who shows up to fight them. It's particularly egregious because Raphael later makes a comment about someday being able to walk around outside freely...despite the fact that he did so earlier that day.
- What Happened to the Mouse?: April is able to get the Turtles back to their normal size with the Eye of Sarnoth's fragment, but Shredder then steals it back. This is done before anyone restores any of the two dozen or so buildings (including the Empire State Building) that Shredder also shrunk. A news report that April delivers says that the "shrinking business" has stopped, so presumably the buildings are OK now?
- Why Did It Have to Be Snakes?: The Turtles encounter a sewer snake while riding on a bar of soap. Leonardo slices off some pieces of soap for the snake to swallow, making it breathe out bubbles, and it slithers away.
