First Look: Sheldon And Penny Have Their Patience Tested On The Big Bang Theory

Penny quizzes Sheldon on pop-culture iconography.

Penny quizzes Sheldon on pop-culture iconography.

After Sheldon decides he'd rather go to a movie screening with his friends than hang out with his girlfriend, he hires Stuart to spend the day shopping with Amy. Plus, Penny finds herself struggling to connect with Leonard's mother, Dr. Beverly Hofstadter (played by guest star Christine Baranski), when she comes to town on the next episode of The Big Bang Theory entitled "The Line Substitution Solution."
Penny almost tricks Sheldon with this image of a reality-TV star.

Penny almost tricks Sheldon with this image of a reality-TV star.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Sheldon and Penny let Leonard play, too.

Sheldon and Penny let Leonard play, too.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Sheldon proudly holds up a helium flashcard.

Sheldon proudly holds up a helium flashcard.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Sheldon smiles at Leonard during the morning quiz.

Sheldon smiles at Leonard during the morning quiz.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
The guys talk at the comic-book store.

The guys talk at the comic-book store.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Something surprises Sheldon while sorting through the comics.

Something surprises Sheldon while sorting through the comics.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Bernadette helps Penny prep food and wine for Leonard's mother.

Bernadette helps Penny prep food and wine for Leonard's mother.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Beverly struggles to let her guard down in front of her new daughter-in-law.

Beverly struggles to let her guard down in front of her new daughter-in-law.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Penny confronts Beverly about building their relationship.

Penny confronts Beverly about building their relationship.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Penny's patience is tested by Leonard's mother.

Penny's patience is tested by Leonard's mother.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Stuart crashes girls' night with apology flowers from Sheldon.

Stuart crashes girls' night with apology flowers from Sheldon.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Raj shows off his sitting stick.

Raj shows off his sitting stick.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Sheldon has words with another movie-goer in line.

Sheldon has words with another movie-goer in line.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Sheldon looks for support during an argument with someone who cut the line.

Sheldon looks for support during an argument with someone who cut the line.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Sheldon embarrasses his friends after an in-line altercation.

Sheldon embarrasses his friends after an in-line altercation.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)
Leonard and Howard look uncomfortable in the movie theater lobby.

Leonard and Howard look uncomfortable in the movie theater lobby.

"The Line Substitution Solution" (Episode 23, Season 9 of The Big Bang Theory)

Watch all-new episodes of 
The Big Bang Theory on Thursdays at 8/7c.