Po scéně, kdy čtyři fyzikové rekonstruují bitvu u Gettysburgu přímo v restauraci, kde Penny pracuje, nabídne Leslie Winkle Leonardovi, jestli by se nechtěl přidat k jejich smyčcovému kvartetu, neboť dva jejich členové museli kvarteto opustit kvůli problémům s radiací. Leonard přijme, což vyústí k "fyzikálnímu" svádění ze strany Leslie, které neskončí ničím jiným než sexem. Když se však Leonard další den v laboratoři hlásí k Leslie, je mu sděleno, že to byla jen jednorázová záležitost.

While eating at the Cheesecake Factory where Penny works, the guys run into Leslie Winkle (Sara Gilbert) and she suggests that Leonard play in her string quartet as they are in need of a new cellist as the other players are uncomfortable near the other guy due to the chance he was irradiated at work. Later, after the practice in Leonard and Sheldon's apartment, Leslie offers herself to Leonard and they have sex together.

Meanwhile, Sheldon is uneasy as to how to act after realizing Leslie slept with Leonard. Later on, Penny congratulates Leonard, and he tries to figure out what Penny's words meant. Leonard eventually decides to pursue a real relationship with Leslie over an imaginary one with Penny. However, when Leonard arrives in the lab, Leslie makes it clear she is not interested in a relationship, and only used him to satisfy her sex drive, realizing she used him for a one-night stand. Leonard later tells Penny, who walks away with a smile on her face, seemingly happy to hear this news.

Recurring character: Sara Gilbert as Leslie Winkle
Note: This episode was selected as a Primetime Emmy Award submission for Johnny Galecki for Outstanding Lead Actor in a Comedy Series, but ended up not receiving a nomination.
Title reference: Sheldon switching his favorite burger restaurant.

== osoby ==			== profese ==
CHuck Lorre	Tvůrce
Bill Prady	Tvůrce
David Goetsch	Televizní scénář

== osoby ==	== postava ==
Johnny Galecki	Leonard Hofstadter
Jim Parsons	Sheldon Cooper
Kaley Cuoco	Penny
Simon Helberg	Howard Wolowitz
Kunal Nayyar	Raj Koothrappali

== osoby ==	== postava ==
Sara Gilbert	Leslie Winkle

== osoby ==	== postava ==