"We wear the mask that grins and lies..."

 
Doctor Who:
"I lied to you, 'cos I liked it.  I could pretend, just for a bit..."

Shakespeare:
"There's daggers in men's smiles"


Serenity:
"They'll come at you sideways.  It's how they think.  It's how they move.  Sidle up and smile, hit you where you're weak.  Sort of man they send believes hard.  Kills and never asks why."