When 'The Big Bang Theory' first came on the air, Penny was a stereotypical dumb blonde, another struggling actress trying to make it in Los Angeles who resorted to working at The Cheesecake Factory to make rent.

Over the years she’s shown significant growth, not just through her relationship with Leonard, but also in realizing that her dreams of being an actress might not come true. It's especially nice to have watched Penny succeed in her pharmaceutical sales this season, even if it wasn’t the career path she’d once dreamed of.

Kevin Smith’s offer to let her audition for “Clerks 3” would have been a dream come true for the old Penny, but it's not so simple anymore. She has a steady job making real money, is it worth giving all of that up to take another shot at acting? That’s what she asks Sheldon, who announces he is no longer telling people what to do and instead encourages her to ask him about trains. Using a clever locomotive analogy, she does get his opinion. Go audition, see how it goes and then figure it out from there.

When she arrives at the casting office, she’s met by a dozen near-identical vapid blondes, some of whom she recognizes from old auditions. It quickly becomes clear that while Penny has changed, her competition hasn’t. The women's comments range from catty to just plain ditzy, but it serves to remind Penny that she needs to move forward, not backward.

Meanwhile, Leonard and Raj team up on a project to discover alien life. They purposely leave out Sheldon and Howard, citing their need to take charge and control every situation they’re in. Of course, once Leonard and Raj actually attempt to get to work, they can barely decide where to begin and debate whether that makes them beta or omega males. Like most “Big Bang” stories, the actual science behind what they’re trying to do is the least compelling part of the story. Watching a bitter Howard make cocktails and snap Instagram pictures with Bernadette in an attempt to make Raj jealous is where the real comedy comes from.

Even funnier is when Raj and Leonard realize their only idea stemmed from Sheldon and Howard in the first place. Defeated, they invite the guys back into the group, only to begin bickering as soon as they have to decide who will be in charge of the meeting. Hurt feelings, old slights and Sheldon’s self-involvement all come out in full force but ultimately the gang is successful.

Perhaps too successful! In the episode's final gag, alien life forms do receive their message — which naturally stars Sheldon — and declare he will make a delicious next meal.