The Big Bang Theory season 7, episode 22 airs tonight on CBS! Here’s the preview, and everything you need to know about “The Proton Transmogrification.”

Television legend Bob Newhart will return to Pasadena (and… Degoba?) when The Big Bang Theory season 7, episode 22 airs tonight on CBS. The episode, titled “The Proton Transmogrification,” will focus on the geeky gang’s preparations for Star Wars Day, as Sheldon struggles with some apparent bad news.

The official synopsis for The Big Bang Theory season 7, episode 22 gives us a hint at what Sheldon might have to be upset about.

Professor Proton helps Sheldon cope with grief, while Leonard turns a relationship milestone into a competition with Penny. Meanwhile, Amy and Bernadette make a “Star Wars Day” gift for the guys.

Last week on The Big Bang Theory, Sheldon’s ongoing breakup with physics inspired Leonard to reinstate “Anything Can Happen Thursday.” But after discovering that Amy and Bernadette were enjoying a secret girl’s night, Penny and Sheldon continued on their own – and the results were pure malarky. Elsewhere, Raj discovered that his girlfriend Emily gets turned on by gore-fest films.

The preview for “The Proton Transmogrification” shows Sheldon and Professor Proton in a very different light than we have ever seen them.

A recent sneak peek from tonight’s episode sets up the Star Wars-centric nature of “The Proton Transmogrification.” Meanwhile, still photos from The Big Bang Theory season 7, episode 22 focus on the challenges facing Sheldon, which may threaten to overshadow the May the Fourth celebrations.

Several of the stills do indicate that something rather sad may have happened – could it really be that we will have to say farewell to Professor Proton this week?

The Big Bang Theory season 7, episode 22, “The Proton Transmogrification,” airs tonight at 8:00 p.m. on CBS.

Do you think the gang will succefully celebrate ‘Star Wars’ Day?