It’s ironic to watch Penny and Leonard argue about money after the highly publicized contract negotiations their portrayers engaged in before the season, which made them some of the highest paid actors in TV. While most viewers can’t relate to the paychecks Kaley Cuoco-Sweeting and Johnny Galecki are receiving, they can relate to the power struggle their characters are engaged in.

Penny's pharmaceutical sales job comes with many benefits, including a company car, which spurs her to sell the car Leonard bought her and give him the proceeds from the sale. He refuses to accept, saying she can keep the money. Penny won’t hear it, as she’s finally earning decent pay and doesn’t want to accept his financial support.

The problem seems momentarily solved when Leonard suggests opening a joint savings account. Unfortunately, this leads to Penny calling him out on the new imbalance in the relationship as her professional success is making her less reliant on him. Leonard reminds Penny of her control issues and the couple decide to talk to the happily married Howard and Bernadette about how they manage their money.

Turns out, Howard’s relationship with Bernadette isn’t all that different than his relationship with his mother. Since Bernadette earns more she offers him an allowance (or as he likes to refer to it, a stipend) and the duo rely on a sticker chore chart to keep things even. This wasn’t exactly what Leonard and Penny were looking for, but Leonard ends up admitting that after seeing his mother emasculate his father for most of his life, he’d be fine with Penny making more money than him. Problem solved?

Meanwhile, Raj breaks Sheldon out of some deep thought to propose that they begin work in abandoned salt mines so Sheldon can continue to study dark matter. Considering the conditions  include excessive heat, dynamite explosions, 12 hour shifts and no toilets, Sheldon is apprehensive. They decide to do a trial run in the university’s steam tunnels to see if they can tough it out.

Raj and Sheldon don’t spend much time doing actual science, since most of their conversations revolve around the dual identities of Superman and Hannah Montanna, but Sheldon does have a breakthrough. He confesses that when it came to studying string theory, he had been a child prodigy. Dark matter was a whole other board game, and he was much less sure of himself.

Citing the Voyager space probe as an example, Raj explains that exploring the unknown is a good thing and implores Sheldon to keep going. Minutes later, however, Sheldon spots a family of rats and hightails it out of the tunnel, leaving poor Raj behind.

If you’re wondering whether the guys came close to achieving their original goal of a 12-hour stay in the tunnel, they did not. Amy clocked them as having lasted just about 11 minutes.