Wacky scenarios turned somber tonight on The Big Bang Theory season 8, episode 15. Here’s what happened in “The Comic Book Store Regeneration.”

Plays well with others

Sheldon is peeved to learn that Amy helped Kripke add a neurobiological element to his string theory research. Even worse, the resulting paper has been very successful.

Sheldon later expresses his anger at Amy’s “betrayal” to Penny. She tries to teach Sheldon how to let go of his feelings of betrayal, but the tables are turned when he reveals that Amy has been not so subtly testing Penny’s intelligence against that of her lab monkeys. Even worse, the idea partly came from Sheldon.

Penny is furious, and throws Sheldon out of her apartment. On the plus side, Sheldon is over the Kripke thing.

Give and take

Mrs. Wolowitz is on vacation in Florida, and asks Howard to check up on Stuart. Howard is irritated by the request, but mollified somewhat when Bernadette reminds him that the comic book store is reopening soon, and things will return to, uh, “normal.”

The gang stops by Stuart’s brand new comic book store, but the fresh setup turns sour when Howard sees that Mrs. Wolowitz has given Stuart some of her furniture to use. Adding insult to injury (or injury to insult?) a furious Howard refuses to leave, reminding Stuart that Mrs. Wolowitz fronted the money for the new store.

It’s totally awkward, and Raj and Leonard make a hasty escape.

Shiny-ish

Leonard and Raj spot Nathan Freaking Fillion while they pick up the food for Stuart’s party. Raj suggests they ask Captain Mal to do a signing at Stuart’s store, and they hesitantly approach.

At first, Nathan Fillion says that he’s not Nathan Fillion, but later admits that he really is Nathan Fillion. He feels bad about brushing off the guys and offers to take a picture. Raj is skeptical, but decides that an irritated Nathan Fillion clone is good enough for Facebook.

We’d take it.

Letting go

Penny confronts Amy about the puzzles, but Amy doesn’t understand why Penny is angry. At the comic book store, Penny shares this with Leonard, who realizes that Sheldon was testing him, too. When asked, Amy and Sheldon still don’t see why Penny and Leonard are hurt.

Meanwhile, Howard is still hot and bothered about the furniture thing, but his anger is interrupted by a phone call.

“You okay?” Leonard asks when Howard hangs up.

“No,” Howard says, tearing up. “My mom died.”

Everyone is shocked by the news; no one is really sure what to do. Surprisingly, Sheldon is one with words of comfort.

“When I lost my own father, I didn’t have any friends to help me through it,” Sheldon says. “You do.”

Howard and Bernadette fly down to Florida, and the rest of the gang reminisce about Mrs. Wolowitz. They drink a toast to Ma — “A loving mother to all of us.”

What did you think of ‘The Big Bang Theory’ season 8, episode 15?