Situation: [s2e1] The Mutation

April O'Neil cuts ties with the Turtles, leading to several episodes where the team operates without their primary human ally.

The primary arc for the first half of Season 2 is established: the Turtles must track down every lost canister before they create more mutants. [S2E1] The Mutation Situation

The Turtles celebrate their victory over the Kraang from the Season 1 finale, but the peace is short-lived. They discover that Shredder has formed an alliance with the Kraang to obtain a fresh supply of mutagen. During a high-stakes interception on a Kraang stealth ship, a mishap causes dozens of mutagen canisters to be scattered across New York City. April O'Neil cuts ties with the Turtles, leading

You can find full episode details and streaming options on platforms like Nickelodeon or through official episode guides on community sites like The Technodrome Forums. They discover that Shredder has formed an alliance