In the Reign episode " Inquisition " (S1E11), Queen Catherine faces accusations of treason and adultery from King Henry, prompting her to expose Bash's past, while Mary and Bash uncover her secret regarding the "castle ghost," Clarissa. The episode features Catherine's trial, a search for damaging secrets, and the reveal of her firstborn daughter's identity, along with insights into Bash's background and a connection to pagan rituals.