Sheldon and Leonard will let scientific ends justify not-super-legal means when The Big Bang Theory 9×06 airs tonight.

The episode, titled “The Helium Insufficiency,” will also feature further romantic developments for Amy. (…or not.)

“In the midst of a nation-wide helium shortage, Sheldon and Leonard take desperate measures to get the supplies they need,” CBS says, “Also, Penny and Bernadette download a dating app on Amy’s phone to try and find her a new man.”

Amy considered moving on from Sheldon in last week’s episode of The Big Bang Theory, when Barry Kripke asked her out on a date. Kripke learned of Amy’s single status as he taught Sheldon, Leonard, Howard, and Raj fencing – which went surprisingly well. What didn’t go well were Sheldon’s subsequent attempts to move on from Amy by asking out every woman in sight; however, Amy found herself deeply upset when Sheldon told her of his potentially romantic activities.

The first sneak peek from “The Helium Insufficiency” shows Sheldon and Leonard dealing with something else that’s missing from their lives – helium. (There is no way to make that sound romantic.)

Apparently, the geeks really need that helium – badly enough to plumb the underbelly of the scientific community. But as it turns out, thugs who do business with scientists aren’t exactly idiots.

The final clip from “The Helium Insufficiency” isn’t about science, but it’s full of gas, as Penny and Bernadette come up with a brilliant way to meddle in Amy’s life.

But for all our skepticism, the still photos from tonight’s episode indicate that the gang certainly gets happy about something. And we sort of doubt it’s helium.

The Big Bang Theory 9×06, “The Helium Insufficiency,” airs tonight at 8:00 p.m. on CBS.

What are your hypotheses for ‘The Big Bang Theory’ 9×06?