Episode 4

S1 E4: Diana and Matthew are now guests of Ysabeau De Clairmont, an ancient vampire and killer of witches, at the family's ancestral home, Sept Tours in France. Ysabeau warns Matthew that his love for Diana puts his entire family in danger. Knox is now back at The Congregation and calls an emergency meeting to discuss Matthew's liaison with Diana, as it violates the rule sanctioning relationships amongst species. This puts Baldwin, Matthew's brother and head vampire at The Congregation, on the spot. Later, Domenico, a vampire sent on behalf of The Congregation, turns up unannounced in France to demand Diana's immediate return, and Matthew receives a call that his research lab has been broken into. Fearing Ysabeau was right with her warning, Matthew resolves to abide by the Congregation rules and leaves for Oxford, just as Ysabeau begins to realise how powerful Diana really is.