S1, E11: When King Henry accuses Queen Catherine of treason and adultery, she sets out to save her life by exposing Bash's dark past. Mary and Bash go on a quest to expose an even more deadly secret from Catherine's past. Meanwhile, Nostradamus reveals the truth about the castle ghost, Clarissa, which shocks everyone. Caitlin Stasey, Anna Popplewell and Celina Sinden and Toby Regbo also star.