Sheldon: At this point, I should inform you that I intend to form my own team and destroy the very bonds that bind your very matter together and reduce the resulting particulate chaos to tears!
Leonard: Thanks for the heads up.
Sheldon: You're welcome. [Turns to leave.] One more thing,
Sheldon: It's on, bitch.
After Sheldon mentions a molecular sieve, they go over to 4a, their apartment. 4a is a kind of molecular sieve.