Complex sentence: The Turtles rise to the surface for the first time since being mutated, and witness April O'Neil and her father Kirby getting captured by the Kraang, a race of brain-like aliens with robotic bodies.
Split into simpler sentences: The Turtles rise to the surface for the first time since being mutated. They witness April O'Neil and her father Kirby getting captured by the Kraang, a race of brain-like aliens with robotic bodies.