Polonius watches as Hamlet and his mother talk. Polonius is hiding behind a curtain hoping that Hamlet doesn't see him. He also has to report back to Claudius who has just put a hit on Hamlet, which should be carried out by Rosencrantz and Guildenstern.
Oh, my offense is rank. It smells to heaven. It hath the primal eldest curse upon't...What if this cured hand, were thicker than itself with brother's blood? And what's in prayer but this twofold force, to be pardoned being down? That cannot be, since I am still possessed, of those effects for which I did the murder:
A villain kills my father, and for that, I, his sole son, do the same villain send...to heaven. Why, this is hire and salary, not revenge.He took my father grossly, full read, with all his crimes broad blown, as flush as may.