When does Invincible return?

The adult animated superhero television series is based on the Image Comics series of the same name. The series stars Steven Yeun, Sandra Oh, and J. K. Simmons as the Grayson family, while the rest of the cast serve as recurring characters. Series has received acclaim from critics for its animation, action sequences, story, voice performances (particularly Yeun and Simmons)
Mark Grayson is a seemingly normal teenager whose father Nolan is the most powerful superhero on the planet. Shortly after his seventeenth birthday, Mark begins to develop powers of his own and learns how to wield them with help from his father. His father turns out to be a member of the Viltrumite Empire bent on intergalactic conquest.