The Blue-eyed Witch is #45 in the Bantam series and one of the last books that has a corresponding UK cover illustrated by Francis Marshall. While in the country, the Marquis of Aldridge rescues Idylla, who has lost her memory and is believed to be a witch by the townspeople. He later discovers a plot against her and falls in love trying to thwart it!
Francis Marshall painted a similar cover for these books. Note our hero in the process of rescuing the heroine. The Bantam cover is set near a lake, where they had planned to drown her. The Arrow cover is set outside his estate and our heroine is dressed in evening gown, as opposed to the day dress she wears in the Bantam cover. Both are beautiful illustrations.
The fear of the unknown obsessed people in early 1800's England and many people were hurt or killed by accusations of witchcraft.