It looks like Sheldon has an important puzzle to solve, but luckily, he has Leonard to help him.
On The Big Bang Theory Season 9 Episode 10, Sheldon tries to figure out why a song is stuck in his head, and that leads him to a surprising revelation.
Check out these photos for a sneak peek of "The Earworm Reverberation."
Solve This Puzzle! - The Big Bang Theory Season 9 Episode 10
Sheldon has a revelation of some sort as he tries to figure out why a certain song is stuck in his head. Is Leonard helping out? Are there equations involved? Most likely!
Penny and Leonard Listen - The Big Bang Theory Season 9 Episode 10
Penny and Leonard listen to an upset Sheldon. Things with he and Amy have taken a turn, and now, he's the one who has made the decision to just be friends. Does he regret it?
What a Happy Couple - The Big Bang Theory Season 9 Episode 10
Leonard and Penny seem like happy newlyweds. And thank goodness, since the start of their marriage was a bit rocky. Still, we have to wonder when they'll move in together for real.
Do Not Give Up - The Big Bang Theory Season 9 Episode 10
Sheldon and Leonard continue trying to solve their problem, and the look on Leonard's face should probably tell us everything we need to know.
This is Getting Serious - The Big Bang Theory Season 9 Episode 10
You know things are getting serious when the guys break out more than one white board to work on their equations. Anyone else wonder what the heck these things really mean?
Bernadette and Amy Talk - The Big Bang Theory Season 9 Episode 10
Some girl time is always a good thing, especially when it's with Bernadette and Amy. The two of them are even enjoying a hot beverage together. But what might they be discussing?