 Kvanvig proposes that quantified expressions are non-rigid. The reason he gives is that quantifiers designate different objects in different possible worlds. “Everyone in Jon’s Logic class must take the final” is about different students in different possible worlds. Were Sussie to have taken the class, the expression would have been about her. But she decided not to take the class, so actually it is not about her. \(Kp\) is an abbreviation for ‘it is known by somebody at some time that \(p\).’ So, \(Kp\) is implicitly quantified. Explicitly it reads \(\exists x\exists t(Kxpt),\) which says there is a being \(x\) and a time \(t\) such that \(x\) knows that \(p\) at \(t\). Accordingly, on this account, the quantified expression that \(Kp\) abbreviates is non-rigid. \(\exists x\exists t(Kxpt)\) is about different beings and times in different modal contexts. For instance, the expression \(\exists x\exists t(Kxpt)\) is about actual beings and times. But embedded in a modal context, e.g., \(\Diamond \exists x\exists t(Kxpt),\) the expression is about possible beings and times. It says, ‘there is a possible world in which there is a being \(x\) and time \(t\) such that \(x\) knows that \(p\) at \(t\).’