A: How is Sarah doing this semester?

B: I was worried that she wouldn’t be able to handle the advanced math class that we moved her into, but she’s been on fire this whole semester.

A: Sarah is very brilliant indeed.

Note: The literal meaning of “on fire” is “aflame,” but this term is often used metaphorically to mean “performing very enthusiastically, adeptly, or successfully” or in slang “very sexy and attractive.”