Chapter Act I of The Winter's Tale - Study Guide by William Shakespeare

"They're here with me already; whisp'ring, rounding
"Sicilia is so-forth": tis far gone,
When I shall gust it last." (1.2.217-219)

Camillo is horrified at Leontes when he realises his state of mind and frankly calls it this diseased opinion. Leontes' response is a petulant denial:

"It is: you lie, you lie:
I say thou liest, Camillo, and I hate thee,
Pronounce thee a gross lout, a mindless slave,
Or else a hovering temporiser that
Canst with both eyes at once see good and evil,
Inclining to them both" (1.2. 299ff)

Camillo's desperation when he is ordered to poison Polixenes is shown when appeals to "thee" instead of the respectful "you" (324) but Leontes is convinced that his jealous madness is a state of heightened, superior perception, and even argues that since it is the last thing he would want to believe, the fact that he believes it shows it is true. Camillo is left with the impossible choice of disobeying his master or committing regicide when Polixenes enters and asks him what is going on, having sensed a change in Leontes' manner. Camillo, unable to lie to him, reveals the poison plot and the reason for it, and Polixenes decides to flee with Camillo.