Complex sentence: The three go after a now undead Lucy, while Dracula pursues Mina, who soon realises Seward was telling the truth when Dracula attempts to bite her, however Arthur is forced to destroy his wife when she attempts to bite him and Seward.
Split into simpler sentences: The three go after a now undead Lucy, while Dracula pursues Mina. Mina soon realises Seward was telling the truth when Dracula attempts to bite her, however Arthur is forced to destroy his wife when she attempts to bite him and Seward.