The Maternal Combustion Season 8, Episode 23 -  Aired April 30, 2015

The Maternal Combustion

When Sheldon and Leonard receive an award for the paper they co-wrote together, their mothers both pay a visit to Pasadena. Meeting for the first time, sparks fly between Mary Cooper and Dr. Beverly Hofstadter when they don't see eye to eye on religion or psychiatry.

Meanwhile, Bernadette has had enough of feeling like a mother to three teenage boys, so Howard, Stuart and Raj are told to clean the kitchen.

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Guest Stars: Christine Baranski as Beverly Hofstadter, Laurie Metcalf as Mary Cooper, Kevin Sussman as Stuart

Writers: Steven Molaro (Story), Tara Hernandez (Story), Jeremy Howe (Story), Chuck Lorre (Teleplay), Jim Reynolds (Teleplay), Maria Ferrari (Teleplay)

Director: Anthony Rich

Viewers: 13.85 million Households Rating: 9/15 Adults 18-49 Rating: 3.4/13

Available on iTunes

Episode Notes

  • The title refers to the heated exchange between Sheldon and Leonard's mothers, Mary Cooper and Dr. Beverly Hofstadter, who meet each other for the first time.

Episode Quotes

Mary Cooper: When your mom gets back, I'm gonna need to apologize for the way I spoke to her.
Penny: Well, come on, she did kinda start it.
Mary Cooper: Doesn't matter. A good Christian would have turned the other cheek. On the other hand, a good Texan would have shot her, so I'll just split the difference.

Leonard: Not once did my mother ever give me any love or affection for just being myself. I always had to earn it.
Mary Cooper: Oh, Leonard, I'm sure she loves you very much. In her own cold godless way.

Mary Cooper: Well, I would have to say when he was thirteen and he tried to build a nuclear reaction in the tool shed.
Sheldon: Ooh, this is a good one.
Mary Cooper: Now, the first thing you need to know about Shelly is, ever since he was a little boy, he was always concerned with the well-being of others. And he didn't think it was fair for people to pay for electricity, so he was gonna power the entire town for free.
Sheldon: Tell her about the uranium. Tell her about the uranium!
Mary Cooper: Oh, well! Well, this is adorable. When he arranged to get some yellow-cake from Chad, I thought he was talking about twinkies from one of his friends.
Sheldon: Yeah. But I wasn't, because I didn't have any friends.
Mary Cooper: No. It turns out this little scallywag was trying to use my Visa card to buy uranium from an African warlord in the country of Chad.

Mary Cooper: At least the bearded man I believe in preaches love and compassion. All yours talks about is why you hold in your poop and want to crawl back inside your mama.

Penny: Leonard, what time does your mom's plane get in?
Leonard: I don't know. Sometime tomorrow morning.
Penny: Don't you want to know for sure?
Leonard: No need to. As soon as she flies into California airspace, I'll feel a disturbance in the Force.

News Stories

Title Date Posted
823 'The Maternal Combustion' Ratings May 1, 2015

Last night's episode of The Big Bang Theory dominated its time period to finish as Thursday night's top-rated broadcast, despite tougher cable competition from the NFL Draft.  Full story

823 'The Maternal Combustion' Press Release April 29, 2015

CBS has issued the press release for tomorrow's episode of The Big Bang Theory, "The Maternal Combustion", the penultimate episode of the season. Laurie Metcalf and Christine Baranski reprise their roles as Sheldon's mother, Mary Cooper, and Leonard's mother, Dr. Beverly Hofstadter, respectively, in the episode.  Full story


While Amy and Penny unpack dinner in the apartment, Penny wonders when Leonard's mother's plane is due in. With Dr. Hofstadter and Mrs. Cooper both coming to town as Sheldon and Leonard receive an award, the guys are worried about how their mothers will get on together. The next day, as they talk on the couch, Mary congratulates Sheldon on the award he and Leonard are receiving. When Mary explains she didn't really understand the paper, Sheldon doesn't miss an opportunity to have a dig at Mary's religious beliefs. Sheldon tells Mary not to talk about religion with Dr. Hofstadter. Meanwhile, as Leonard and Beverly climb the stairs, Beverly interrogates Leonard about his and Penny's relationship. Leonard tells Beverly to be respectful of Mary's beliefs.

When Leonard and Beverly reach the apartment, Sheldon introduces Beverly to Mary. When they make small talk about their flights there, Mary says that it was like someone - not saying who - was watching over the plane. Beverly wonders if she's kidding. Elsewhere, Bernadette walks into her kitchen to find Stuart in his underwear. Bernadette tells him one of the rules for living at her house is he must wear pants. Then, Howard enters in his boxers.

Back in the apartment, Beverly asks Mary what Sheldon was like as child. Mary tells her the story of how Sheldon tried to buy yellowcake uranium from a warlord in Chad. Feeling left out, Leonard asks Beverly to tell a story about his childhood, but her storytelling leaves a lot to be desired. Elsewhere, when Bernadette returns home after running errands, she finds Howard, Raj and Stuart lounging about. Bernadette tells them she's fed up of feeling like the mother of three lazy teenagers, and orders them to tidy up the kitchen.

As Sheldon shows Beverly a picture of his graduation, Penny arrives at the apartment. Fed up of the focus being on Sheldon, Leonard demands to talk to him alone. In Sheldon's room, Leonard tells him to stop hogging his mother's attention. Back in the living room, after Penny mentions she and Leonard haven't set a date for their wedding, Mary comments that they're already married in the eyes of God, eliciting an "Ugh." from Beverly. Insulted, Mary asks Beverly if the bible is "ugh" to her. Beverly apologizes, saying as a psychiatrist she recognizes how important superstitions can be to people. Mary objects the description of religious beliefs as "superstitions" and fires back a comment about Beverly's psychiatric books. When Sheldon and Leonard emerge arguing with each other, Sheldon says it isn't his fault if Beverly likes him more. Leonard tells Sheldon that Beverly likes everyone more than she likes him.

As Stuart and Raj help Howard tidy up the kitchen, they tell him it's a good thing that Bernadette is no longer babying him, like his mother used to. Howard realizes it's time for him to step up and be a man, starting with taking the garbage out. When the garbage splits as he carries it, he cries out to Bernadette that he's made a mess. Elsewhere, Sheldon and Beverly have a drink in a cafe. Beverly apologizes to Sheldon for upsetting his mother. Having seen a parenting style that is diametrically opposed to her own, and the prodigious offspring it produced in Sheldon, Beverly wonders about her parenting style. Sheldon points out that Mary's affectionate parenting also produced two "mouth-breathing idiots". Back at the apartment, Leonard and Penny talk to Mary. Mary apologizes to Leonard for the way she spoke to Beverly. Mary comforts Leonard that his mother loves him very much "in her own cold, Godless way". 

Bernadette congratulates the guys on cleaning the kitchen all by themselves. The guys are proud, until Howard's shoe and then sock stick to the floor. Back at the apartment, Beverly and Mary shake hands and agree to respect each other's beliefs. Before Leonard takes her back to her hotel, Beverly tells him there's something she needs to say. Beverly tells him she realized today there's more than one way to raise a child, therefore she would like to initiate a new protocol wherein she showers him with unconditional love. Beverly and Leonard then hug awkwardly. Back in Howard and Bernadette's kitchen, Howard, Raj and Stuart sing "It's a Hard Knock Life" as they continue to tidy up.