Well, we still have no idea about what monster haunts the forest around the castle, but we do have a better idea about who the monsters are within the castle walls after Reign Season 1 Episode 17.
Catherine's brutal murder of Mary's countrymen was her boldest act yet--and considering that Catherine has her own room devoted solely to poison, that's really saying something.
Will Mary retaliate?
Okay, how will Mary retaliate? Nostradamus appears to be on vacation, so they only way to find out is to watch Reign online.