Bradley Cooper had a surprise guest starring role in the Season 4 premiere of "The Righteous Gemstones" on Sunday, setting the tone for the final season of HBO's hit comedy.

The season 4 premiere of The Righteous Gemstones is set in 1862 and stars Bradley Cooper. Here is how it happened & when the regular cast will return.

I sent him the script and he called me back pretty quickly,” McBride tells PEOPLE before explaining what happened nextBradley Cooper may have needed just a little nudge to sign on to appear in the fourth and final season of The Righteous Gemstones.