[s12e17] The Conference Valuation -

Back at home, Howard is left alone with the kids and invites the guys over for company. The day takes a turn when Sheldon finds a book on developmental experiments for children.

Sheldon and Amy use the children to test cognitive and motor skills, much to Howard's amusement and Leonard's distress. [S12E17] The Conference Valuation

Penny and Bernadette travel to San Diego to promote a new drug. Penny, thriving in her role as a sales lead, catches the attention of Danny, a representative from a rival company that Bernadette despises. Back at home, Howard is left alone with

In episode " The Conference Valuation " (S12E17), the story splits between a high-stakes pharmaceutical convention in San Diego and a chaotic "science day" back in Pasadena. The Pharmaceutical Convention Penny and Bernadette travel to San Diego to

Bernadette eventually fights to keep her, and Penny declines the rival offer, though Bernadette secretly keeps a napkin with Danny's high-salary offer hidden from Penny. The "Guinea Pig" Day

It is revealed that Amy intentionally brought the book to spark Sheldon's interest in having their own children—a plan that seemingly works as Sheldon begins discussing the logistics of having triplets or quintuplets.