The Shredder wants to start an army called the Foot Clan, and he’s enlisting street urchins.
The turtles go through a lot of peril (including escaping a burning building!) on the way to the Shredder, but it’s their master, Splinter, in the end who defeats him.
This is fitting since Splinter wants revenge for his master’s murder at the hands of the Shredder when he was once known as Oroku Saki.
The first and best Turtles movie, this is the film that’s closest to their gritty origin, and it even takes story lines from the comic book series.