"The Big Bang Theory" Season 7 is knocking at the door called end, as it is the penultimate episode this Thursday, May 01 2014. In this episode, Bob Newhart returns to reprise his role as Dr. Arthur Jeffries, popularly known as Professor Proton. The spoilers of the episode suggest that it is likely to be Newhart's final appearance for "The Big Bang Theory." Sheldon will be seen grieving the loss of his childhood T.V. idol.

The Episode 22, titled "The Proton Transmogrification," of "The Big Bang Theory" Season 7 is timed to celebrate the Star Wars Day, which is annually celebrated by the fans of Star Wars franchise on May 04.

Professor Proton will appear to Sheldon as his own Jedi master, Today Entertainment's reports. According to the spoilers leaked online, Leonard gives Sheldon the sad news that Professor Proton has passed away. The funeral is on Star Wars Day and Sheldon tells Leonard that he is not upset and plans to celebrate the day as the gang had planned. However, the spoilers suggest that on the day, Sheldon shows all the signs that he is upset about Professor Proton's death. In Sheldon's dreams, Professor Proton visits him.

The sudden passing away of Professor Proton make Leonard and Penny talk about their relationship. Penny proposes to Leonard, again. She has previously proposed to Leonard in a drunken state, and he had said no at the time. The spoilers indicate that Leonard again says no, adding that he loves her very much.

Officially Synopsis of "The Big Bang Theory" Season 7 Episode 22, "The Proton Transmogrification," : "A grief-stricken Sheldon receives counseling from his childhood TV idol, Prof. Proton (Bob Newhart), while Penny and Leonard reach a relationship milestone and turn it into a competition and Bernadette and Amy turn "Star Wars Day" into a special event for the guys."

[Youtube/The Big Bang Theory]

For this episode, "The Big Bang Theory" has teamed-up with Lucasfilm's Industrial Light & Magic to re-create Dagobah for the episode. Also, they have provided props such as light saber. Moreover, Lucafilm's experts consulted on the episode and visited the set to see the production.