‘The Big Bang Theory’ Spoilers: Online Bully Tortures Sheldon; Return Of Serial Ape-ist

Tonight’s episode of The Big Bang Theory is called “The Troll Manifestation,” and the trolls the guys encounter are of the internet kind. Leonard and Sheldon co-author a paper and receive feedback through online message boards. One particularly nasty commenter eventually meets Sheldon face-to-face, and it turns out to be “the last person” Sheldon expects, according to TV Guide.

Executive producer Bill Prady used colorful language to describe Sheldon and Leonard’s internet experience.

“They get drawn into the world of Internet snark and flamewars in the comment boards.”

Meanwhile, the women have a girls’ night that finds them digging up each others’ embarrassing moments. For Kaley Cuoco’s Penny, that means the return of Serial Ape-ist, the low-budget flick she would probably rather not have listed on her acting resume. There’s also what ET Online calls a “shockingly embarrassing” online clip of Bernadette and Little House on the Prairie fan fiction written by Amy.

ET also revealed tonight’s episode has a “trick up its sleeve,” without providing details. A guest star might be in the works, since the site alluded to the unexpected appearance of Billy Bob Thornton a few episodes back.

Tonight’s episode comes a mere two weeks before what is sure to be an emotional episode. In “The Comic Book Store Regeneration,” the show plans to pay tribute to actor Carol Ann Susi, who played the never-seen, always-heard mother of Howard Wolowitz. Susi passed away in November. The show will feature the re-opening of Stuart’s comic book store, a fixture of the show until it was devastated by fire at the end of last season.

Although it has not been revealed how The Big Bang Theory will approach the loss of Susi, blogger CarterMatt weighed in that the death of Debbie Wolowitz is appropriate.

“There were and are many different options as to how the writers of the show could handle this, but we know that they are not recasting the character. Nobody wants to see Howard suffer, but killing off the Debbie character seems to be the only right move to make. It is realistic in that death is a part of life, and another Chuck Lorre series, ‘Mom,’ recently tackled some hard subjects. We know that these sitcoms are not shy about taking on hard issues when they are appropriate.”

The February 19 episode will also feature a cameo by Castle star Nathan Fillion in a separate storyline. Fillion will play himself. The actor’s short-lived series Firefly has been long-written into the Big Bang Theory scripts as a favorite of Sheldon’s, who laments its cancellation. Fillion also starred on the final season of Buffy the Vampire Slayer, which Leonard tried to get Penny to watch earlier in the series.