The Big Bang Theory Season 7 Episode 8
The Itchy Brain Simulation
When Leonard finds a never-returned DVD that was rented on Sheldon's account, Leonard tries to make amends. Sheldon has him wear an itchy sweater to understand how Sheldon's mind gets itches until he resolves the DVD.
The DVD shop closed, so Leonard tracks down the owner. He died. Leonard goes in the search of his relatives. When he doesn't find any, he gives up.
Raj's ex-girlfriend, Lucy, ends up sitting in Penny's section at the restaurant. Penny asks why she broke up with Raj by email. Raj is upset that Penny told Lucy he was upset over the break up until Lucy texted him to meet for coffee. Raj thinks they might get back together, but all Lucy just wants to apologize. She's in a new relationship.