Leonardo, Raphael, Donatello, and Michelangelo prepare to defeat a familiar enemy, but are faced with a new power they’ve never seen, in the all-new hour-long special episode of Tales of the Teenage Mutant Ninja Turtles, “When Worlds Collide,” premiering Sunday, June 18, at 9:00 a.m. (ET/PT) on Nickelodeon.

The Newtralizer returns to New York City more powerful than ever before and joins forces with a dangerous, yet unexpected ally. With the help of Mona Lisa, the highly skilled Salamandrian warrior played by returning guest star Zelda Williams (The Legend of Korra), the Turtles fight back to defend their city.

Check out a new clip from the episode in the player below:

Source: Nickelodeon