The Beginning of the End
Teenage Mutant Ninja Turtles (1987) episode

Title screen
Season Code: 10
Episode: 02
Original airdate September 21, 1996
Written by Jeffrey Scott
Episode chronology
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"The Return of Dregg" "The Power of Three"
Teenage Mutant Ninja Turtles 1996 Season
List of Teenage Mutant Ninja Turtles episodes


  1. "The Return of Dregg"
  2. "The Beginning of the End"
  3. "The Power of Three"
  4. "A Turtle in Time"
  5. "Turtles to the Second Power"
  6. "Mobster from Dimension X"
  7. "The Day the Earth Disappeared"
  8. "Divide and Conquer"

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This article is about the 1987 series episode. For the 2003 series episode with a similar name, see Beginning of the End.

"The Beginning of the End" is an episode of the 1987 Teenage Mutant Ninja Turtles cartoon series.

Plot Synopsis

Donatello hooks the horribly hyper-mutated Leonardo up to his equipment in the hopes of restoring him to normal. It seems to work, restoring Leonardo to his usual state. However, the other Turtles don't notice that his legs are suddenly glowing.

Lord Dregg is planning to use the chip of mutated shell to further mutate the Turtles "out of existence" with mutinite. Mung informs him that they don't have any of the substance because it's only found in Dimension X, but plutonium will work instead.

Leonardo begins to feel sick and hyper-mutates again, attacking his brothers before fleeing the lair. He continues causing mayhem and property destruction (especially of cars) before heading to the nearest hockey rink and destroying most of the interior.

Dregg's forces invade a nuclear power plant and demand all the plutonium.

As the Turtles corner Leonardo, Dregg's shuttle arrives and starts blasting at them before kidnapping the hypermutant. Donatello manages to sneak on board while the other turtles and Carter try to save a train that's about to be wrecked.

April is trying to have a "Turtle-free" busting of a car chop-shop when Dregg's shuttle crashes through the wall, and the hyper-mutated Leonardo is unloaded. The microbots are instructed to build a plutonium ray, which will be used on Leonardo to make him even more dangerous. April tries to alert the Turtles, but is caught.

Leonardo is shot with the plutonium ray before Donatello can do anything, which causes him to revert to his usual state. Donatello intervenes before April can be turned into a cyborg, and the other Turtles arrive just in time to back him up.

Dregg reveals that the plutonium is causing Leonardo to become even more unstable, meaning that he will reach critical mass within thirty minutes. He hyper-mutates again as Dregg and his minions leave, attacks the others and carries off April. Carter and Donatello go after Leonardo, while Michelangelo and Raphael go after Dregg's chemicals, in the hope of formulating a cure. They successfully steal the chemicals, but their escape causes the ship to catch fire and crash.

At the lair, Leonardo is about to go critical when they return with the chemicals and manage to turn him back to normal yet again.

A microbot on Leonardo reports on his return to his old self. Dregg says that Leonardo may look normal, but that his genetic structure has been altered somehow.


Home media releases


  • Teenage Mutant Ninja Turtles Volume 1
  • Teenage Mutant Ninja Turtles: The Complete Final Season
  • Teenage Mutant Ninja Turtles: The Complete Classic Series Collection


Animation Errors

  • As mutated Leonardo is breaking a support beam in the hockey stadium, the support beam turns purple for a few frames.
  • When April brings up Otto Wrecker's police file, his name is written in red, but in the next shot it's in black.
  • When the Turtle Van backs up onto the bridge to stop mutated Leonardo, the lettering on the front of the Turtle Van is black instead of white.
  • When Michelangelo searches for the 333 South Simpson St./Simpleton Blvd. addresses, he randomly types the letters "ZZTZT" instead of the actual address. The keyboard doesn't even have any numbers on it.
  • When Raphael, Michelangeo and Carter arrive at 333 South Simpleton Blvd., the lettering on the front of the Turtle Van is again black instead of white.
  • When Raphael and Michelangelo leave the warehouse to go get the chemicals Dregg used on Leonardo, the damage to the back of the Turtle Van caused on the bridge by Dregg's henchmen has disappeared. The lettering on the front is also black instead of white.
  • When Donatello and Carter commandeer a garbage truck, the orange rectangle below the headlights (badly drawn licence plate?) disappears several shots later.

Continuity Errors

  • In this episode, the licence plate on Carter's motorcycle is 17952, but in season 9's first episode (Carter's first appearance), his licence plate is 17987.


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