The Big Bang Theory Season 10 Episode 15 spoilers: Sheldon Betrayed By Leonard and Howard

The upcoming episode, titled "The Locomotion Reverberation," will focus on Sheldon's role in slowing down the progress of an invention that he is working on with Leonard and Howard. As a result, the duo comes up with an ingenious plan to sidetrack his attention from the project.

Howard and Leonard will make Sheldon the in charge of engineering and make him accountable for the locomotive. Naturally, Sheldon is pleased with the task due to his fondness for trains, unaware of his team members' intentions, Yahoo reported.

However, rather than being distracted, Sheldon gets more intent on finishing the invention project as early as possible. But an unfortunate event will pull the three of them away from the project and likely lead to its termination.

Meanwhile, according to "The Big Bang Theory" Season 10 Episode 15 spoiler guide, Bernadette (Melissa Rauch) will finally go out with the girls for the first time after giving birth to Halley. Amy (Mayim Bialik) and Penny (Kaley Cuoco) ask Bernadette to go out with them in the upcoming episode. To help her take a break from being a hands-on mother, Raj (Kunal Nayyar) and Stuart (Kevin Sussman) offer to babysit Howard and Bernadette's daughter in her parents' absence.

In the show's episode 14, "The Emotion Detection Automation," Sheldon decides to try beta testing a machine from MIT that can help him read emotions, after spending an entire life unable to recognize social cues. Amy, as always, encourages Sheldon to go ahead with it. At the same time, Raj decides to get to the bottom of his single status and gathers all his ex-girlfriends to understand the reason. However, it all goes poorly for Raj as the girls were not only critical but also seeing other men.