Possible quotes or references to literature, history, or philosophy would strengthen the essay. For example, using a quote about power's corrupting influence. Also, maybe reference the concept of the body politic, where the queen's corruption mirrors the kingdom's ills.
Literary examples could include Shakespeare's Lady Macbeth, whose guilt contaminates her soul, or maybe a more modern example. Also, maybe fairy tales or myths where a queen is poisoned physically and metaphorically.
Need to avoid going off track. Stay focused on how contamination (literal and metaphorical) corrupts both the body and the soul of the queen, leading to downfall. Use examples to illustrate each point.