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This article contains plot details from the latest books.
Lord Cassius is Keefe's father, and part of the Sencen family. He worked for the council and is a powerful empath. Lord Cassius's wife is Lady Gisela. In Keeper of the Lost Cities, he meets Sophie briefly on the staircase leading down from the Level Four wing at Foxfire, at the end of Midterms celebration. He took quite an interest in Sophie Foster, hinting that he knew she was the mystery prodigy that Sir Tiergan was mentoring. Lord Cassius thinks Keefe should stop wasting his time and work harder in school. Lord Cassius wrote a book about Empathy, called The Heart of the Matter. Keefe, who had to read it in Book Four, described his father as a "torturer of innocent readers," but he did say he learnt a bit about head and heart emotions. He is also told to be not a great father, and has constantly belittled his son, Keefe.
His name, Cassius means "empty", or "vain", referring to his character.
Lord Cassius is described as taller man with much of Keefe's characteristics, but with blonde, slicked back hair and neater attire.
- Lady Gisela (Wife/enemy)
- Keefe (son/annoyance)
Lord Cassius does not have a good relationship with his son. He constantly makes rude and sharp remarks about and to his son.
Sophie meets Keefe and Lord Cassius in the Level 4 wing at Foxfire. She notices that Keefe is always down when his father is there. Lord Cassius calls Tiergan an "infamous mentor" when he (Tiergan) saves Sophie from sharing her identity as a telepath.
After Sophie's telepathy is revealed to the public, Keefe describes his father as very smug. Apparently he had guessed that Sophie was Tiergan's prodigy, and Keefe says that his father always has to be right, and he always is.
During Book 3: Everblaze, Keefe believes Lord Cassius works for the Neverseen but it is Lady Gisela who is working for the evil organization. Lord Cassius was completely blind to the fact that she was manipulating him.
After being betrayed by his wife, Lord Cassius and a few telepaths search through his memories for any information about the Neverseen.
In Book 6: Nightfall, Lord Cassius tells Keefe and Sophie where Vespera hid her signature in Atlantis, proving he is somewhat worthy to be apart of The Black Swan, which he later joins. It was said earlier that Fitz had suspected Lord Cassius to have been the one to break his wife out of jail, which is something Keefee severely doubts, stating that his father cares more about his reputation than to rescue her.