The Big Bang Theory has landed some big names to help it go out with a bang. Now in its final season, the show has cast Sean Astin and Kal Penn to play scientists in the second half of Season 12, set to air in 2019. The duo will help Sheldon and Amy confirm their theory of super-asymmetry which they were obsessed with throughout the first lot of Season 12 episodes, as the mid-season finale ended upon them realizing the theory’s potential.

Astin and Penn will play Dr. Campbell and Dr. Pemberton respectively, as they will join Jim Parsons and Mayim Bialik who play the well-known (now married) Sheldon Cooper and Amy Farah-Fowler respectively. The fact that the show has brought on these big names to help Sheldon and Amy navigate their theory signifies its importance, and possibly hints at the manner in which showrunner Chuck Lore and his team intends to conclude the series.

While Astin hasn’t commented on the story yet, Kal Penn made his excitement known through an Instagram post today.

Both Astin and Penn are well-known actors. Astin is largely recognized for his role as Samwise Gamgee in Peter Jackson’s The Lord of the Rings series of movies and more recently his run in Stranger Things 2. Penn on the other hand is most known for his role in the raunchy Harold and Kumar movies among others.

The Big Bang Theory is scheduled to resume airing at an as yet unspecified date in January 2019, although Penn’s post suggests the episode featuring him could air as early as next week. Let us know what you think of this casting in the comments below.